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NX Nastran 6.1 ReleaseGuide

Proprietary & Restricted Rights Notice

© 2009 Siemens Product Lifecycle Management Software Inc. All Rights Reserved.This software and related documentation are proprietary to Siemens Product LifecycleManagement Software Inc.

NASTRAN is a registered trademark of the National Aeronautics and Space Administration.NX Nastran is an enhanced proprietary version developed and maintained by SiemensProduct Lifecycle Management Software Inc.

MSC is a registered trademark of MSC.Software Corporation. MSC.Nastran and MSC.Patranare trademarks of MSC.Software Corporation.

All other trademarks are the property of their respective owners.

TAUCS Copyright and License

TAUCS Version 2.0, November 29, 2001. Copyright (c) 2001, 2002, 2003 by Sivan Toledo,Tel-Aviv Univesity, [email protected]. All Rights Reserved.

TAUCS License:

Your use or distribution of TAUCS or any derivative code implies that you agree to thisLicense.

THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTYEXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.

Permission is hereby granted to use or copy this program, provided that the Copyright,this License, and the Availability of the original version is retained on all copies. Userdocumentation of any code that uses this code or any derivative code must cite the Copyright,this License, the Availability note, and "Used by permission." If this code or any derivativecode is accessible from within MATLAB, then typing "help taucs" must cite the Copyright,and "type taucs" must also cite this License and the Availability note. Permission to modifythe code and to distribute modified code is granted, provided the Copyright, this License, andthe Availability note are retained, and a notice that the code was modified is included. Thissoftware is provided to you free of charge.

Availability

As of version 2.1, we distribute the code in 4 formats: zip and tarred-gzipped (tgz), with orwithout binaries for external libraries. The bundled external libraries should allow you tobuild the test programs on Linux, Windows, and MacOS X without installing additional

software. We recommend that you download the full distributions, and then perhaps replacethe bundled libraries by higher performance ones (e.g., with a BLAS library that is specificallyoptimized for your machine). If you want to conserve bandwidth and you want to installthe required libraries yourself, download the lean distributions. The zip and tgz files areidentical, except that on Linux, Unix, and MacOS, unpacking the tgz file ensures that theconfigure script is marked as executable (unpack with tar zxvpf), otherwise you will have tochange its permissions manually.

Contents

ILP-64 Executable Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2New ILP-64 Executable on Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2New “nastran64L” and “nxn6p1L” Commands . . . . . . . . . . . . . . . . . . . . . . 1-2Additional ILP-64 Executable Information . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Multi-body Dynamic Software Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . 2-5MBDEXPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8MBDRECVR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30

Rotor Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44ROTORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-81

Grid Point Force Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-85GPFORCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-85

Additional Dynamics Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-88

External Superelement Enhancements . . . . . . . . . . . . . . . . . . . . . . . 3-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-92NX Nastran 6.1 Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-92Superelement Workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-93Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-95Updated EXTSEOUT Case Control Command . . . . . . . . . . . . . . . . . . . . 3-101

EXTSEOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-101

Contact Enhancements for Solutions 101, 103, 111, 112 . . . . . . . . . . . 4-1

Stopping a Non-Converged Contact Solution . . . . . . . . . . . . . . . . . . . . . 4-110Automatic/Adaptive Penalty Stiffness Options (Beta Functionality) . . . . . . 4-110Penalty Factor Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-111Contact Conditions with the Iterative Solver (Beta Functionality) . . . . . . . 4-115Updated BCTPARM Bulk Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-117

BCTPARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-117

Surface-to-Surface Glue Enhancements . . . . . . . . . . . . . . . . . . . . . . 5-1

Glue Refinement Supported on Shell Element Regions . . . . . . . . . . . . . . . 5-124New Weld-Like Glue Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-124

Automatic Penalty Stiffness Option (Beta Functionality) . . . . . . . . . . . . . 5-125Updated BGPARM Bulk Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-126

BGPARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-126

Element Additions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Pyramid Element Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-130CPYRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-132PSOLID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-134PLOAD4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-141CHBDYE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-144GEOMCHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-149

CROD and CBAR Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-159New Axisymmetric Elements Supported SOL 200 . . . . . . . . . . . . . . . . . . 6-161Damping Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-165

PBUSH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-165PBUSHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-168

Nonstructural Mass Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-170NSM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-171NSM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-171NSM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-172NSMADD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-174

CWELD/CFAST Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-175CWELD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-175CFAST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-182

DMP Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

New Multilevel RDMODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-186GDMODES Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-187

Numerical Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-192MPYAD Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-192SMPYAD Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-193

Acceleration Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Acceleration Load Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-196ACCEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-200ACCEL1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-202

Improved RMAXMIN Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

RMAXMIN Output Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-206Updated RMAXMIN Case Control Command . . . . . . . . . . . . . . 10-211

Pyramid Element Verification Test Results . . . . . . . . . . . . . . . . . . . 11-1

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-216Solid Cylinder/Taper/Sphere — Temperature . . . . . . . . . . . . . . . . . . . . 11-216Thick Plate Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-222Deep Simply Supported "Solid" Beam . . . . . . . . . . . . . . . . . . . . . . . . . 11-228Simply Supported "Solid" Square Plate . . . . . . . . . . . . . . . . . . . . . . . . 11-232Simply Supported "Solid" Annular Plate . . . . . . . . . . . . . . . . . . . . . . . 11-237Cantilevered Solid Beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-241Solid Cylinder in Pure Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-245Internal Pressure on a Thick-Walled Spherical Container . . . . . . . . . . . . 11-252Internal Pressure on a Thick-Walled Infinite Cylinder . . . . . . . . . . . . . . 11-258Prismatic Rod in Pure Bending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-264Thick Plate Clamped at Edges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-270Hollow Sphere - Fixed Temperatures, Convection . . . . . . . . . . . . . . . . . 11-275Hollow Sphere with Two Materials - Convection . . . . . . . . . . . . . . . . . . 11-279Orthotropic Cube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-284

Upward Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

Updated Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-289New Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-310Updated Datablocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-314Updated and New Subdmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-319

System Description Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1

Chapter

1 ILP-64 Executable Enhancements

2 Introduction

1.1 IntroductionIn response to larger memory demands, some NX Nastran executables arecompiled with a 64-bit integer size. The 32-bit integer executables (ILP-32 andLP-64) can allocate up to 8 Gb of memory, while the 64-bit integer executables(ILP-64) can allocate approximately 20 million terabytes. Practically speaking,there are no machines currently supporting more than half a terabyte, thus theamount of memory the ILP-64 executables can allocate is only limited by theamount of memory installed on the machine.

ILP-64 executables are provided for most, but not every platform in which NXNastran supports. See the System Description Summary chapter at the end of thisrelease guide for a list of supported platforms, executable types, and requirementsto run NX Nastran 6.1.

1.2 New ILP-64 Executable on WindowsAn ILP-64 executable is now available on Windows with NX Nastran version6.1. When installing NX Nastran on a Windows 64-bit machine and the64-bit installation option is selected, both the LP-64 and ILP-64 executableswill be installed. The bin directory (install_location/bin/) will have the new“nastran64L.exe” command to run ILP-64 jobs, and "nastran64.exe" to run LP-64jobs.

See the readme.txt file provided at the top level of the installation for all Windowsinstallation notes.

Note

The bytes_per_word is 4 when the ILP-32 and LP-64 executables are used,and is 8 when the ILP-64 executable is used. This difference is importantwhen you are specifying memory with the “memory” keyword. See the“memory” keyword in the NX Nastran Quick Reference Guide for moreinformation.

1.3 New “nastran64L” and “nxn6p1L” CommandsThe nastran command located in the bin directory (install_location/bin/) is used torun NX Nastran jobs. The basic input format is

nastran input_data_file.dat keywords

or

nxn6p1 nastran input_data_file.dat keywords

Additional ILP-64 Executable Information 3

when running NX Nastran jobs or utilities.

Now in addition to the “nastran” and “nxn6p1” commands, the new "nastran64L"and “nxn6p1L” commands exists in the bin directory for the platforms whichsupport both LP-64 and ILP-64 executables. The new “nastran64L” and “nxn6p1L”commands will run the ILP-64 executable.

For example,

nastran input_data_file.dat keywords

or

nast6p1 input_data_file.dat keywords

or

nxn6p1 nastran input_data_file.dat keywords

will run the executable selected by the arch keyword, and

nastran64L input_data_file.dat keywords

or

nxn6p1L nastran input_data_file.dat keywords

will run the ILP-64 executable.

The following platforms support both LP-64 and ILP-64 executable types in NXNastran 6.1:

• Itanium HP-UX

• Windows 64-bit

• X86-64 Linux

• Itanium Linux

• IBM RS/6000 - AIX (64-bit)

• SGI Altix

1.4 Additional ILP-64 Executable InformationThis section provides important information when running the ILP-64 executabletype.

4 Additional ILP-64 Executable Information

ILP-64 executable file formats

The ILP-32 and LP-64 executable types both write binary output files as 32-bit.However, the ILP-64 type produces a different binary file format since all integersand floating point data are written out with a 64-bit precision. Depending on theuse of the binary output files from a 64-bit machine, you may need to convert a64-bit files’s format back to 32-bit. For example, post-processors currently onlysupport 32-bit integers, thus the need to convert .op2 files to 32-bit. Two systemcells are available to convert binary output files from 64-bit machines to 32-bit:

• OP2FMT - Determines if output2 binary results files are written as 32-bit or64-bit when using an ILP-64 executable type.

= 0 (default) If PARAM,POST < 0, the .op2 file is converted to 32-bit. If not,the .op2 file is written as 64-bit.

= 1 The .op2 file will always be written as 32-bit.

• OP4FMT - Determines if output4 binary results files are written as 32-bit or64-bit when using an ILP-64 executable type.

= 0 The .op4 file is always written as 64-bit from an ILP-64 executable.

= 1 (default) The .op4 file will always be written as 32-bit.

When importing an input2 or input4 file into a solution on ILP-64, NX Nastranwill auto detect the type of file and performs data conversion when necessary. Thisautomatic conversion includes both the 32-bit integer to 64-bit and/or the endiantype. If a conversion is necessary, only those datablocks which have NDDL definedwill be imported. All other datablocks are skipped.

In addition to binary file format changes, the .f04 and .f06 output files will have thefollowing differences when written from ILP-64 machines:

• The matrix trailers and the format of floating point numbers will change sinceall matrices that were double-precision will now show as single-precision.

• The exponent descriptor will be an “E” instead of a “D”.

ILP-64 Limitations

The ILP-64 executables have the following limitations:

• Only those data blocks that are NDDL defined cam be converted from 64-bitto 32-bit. See chapter 3 of the NX Nastran DMAP Programmer’s Guide formore information on NDDL.

• All .op2 files written during a solution are in the same precision format, thatis, they are all either 32-bit or 64-bit precision.

Chapter

2 Dynamics

2.1 Multi-body Dynamic Software Interfaces

Consolidated Inputs for ADAMS and Recurdyn Multi-bodySolutions

For RecurDyn and ADAMS multi-body solutions, this release provides consolidatedinput commands for:

• Export

• Results recovery

Export

A RecurDyn Flex Input file (RFI) or an ADAMS modal neutral file (MNF) can beexported from an NX Nastran modal solution to represent a flexible component in amulti-body, dynamics analysis. These files contain reduced order matrices from themodal solution (SOL 103) results. You can then import the RFI or MNF files intoRecurDyn or ADAMS, respectively, and use them to represent a flexible componentin a multi-body dynamics analysis. The NX Nastran RFI/MNF export capabilitystreamlines the process of creating flexible components from FE models, making itpossible to obtain more accurate results from multi-body simulations.

In earlier releases you could use the RECURDYNRFI or ADAMSMNF casecontrol commands to request RFI or MNF file export, respectively. Startingwith this release, you can use a single case control command, MBDEXPORT, torequest either an RFI or MNF. The format is similar to the RECURDYNRFIand ADAMSMNF case control commands, except the MBDEXPORT case controlcommand includes the describers "RECURDYN" and "ADAMS" for selecting theflexbody file type.

The existing ADAMSMNF case control command will be maintained; however, theRECURDYNRFI case control command will be replaced by the new MBDEXPORTcommand. All references to the existing RECURDYNRFI case control commandwill be removed from the documentation in version 7.0.

6 Multi-body Dynamic Software Interfaces

The new MBDEXPORT case control command is included at the end of this section.Example input files for flexbody export and results recovery are also included forboth RecurDyn and ADAMS.

Results recovery

In earlier releases, the ADMRECVR case control command was used to recoverstresses, strains, and element forces from an ADAMS flexbody in a final NXNastran results recovery solution.

Starting with this release, you can use a single case control command,MBDRECVR, for results recovery from either a RecurDyn flexbody or an ADAMSflexbody.

The results recovery solution uses a component modal definitions file fromRecurDyn or ADAMS, along with an optional results recovery OUTPUT2 file,which can be created by NX Nastran during the original “export” solution (mostefficient method), or it can be recalculated during the final recovery solution. Theresulting results can be written to an OUTPUT2 file and imported into an NXNastran compatible post-processor.

The existing ADMRECVR case control command will be maintained.

The new MBDRECVR case control command is included at the end of this section.Example input files for flexbody export and results recovery are also included forboth RecurDyn and ADAMS.

RecurDyn and ADAMS Flexbody Procedure

The following steps describe the RecurDyn and ADAMS flexbody procedures usingthe new MBDEXPORT and MBDRECVR case control commands.

1. Initial NX Nastran Sol 103, RFI creation for RecurDyn, or MNF creation forADAMS.

The MBDEXPORT describers "RECURDYN" and "ADAMS" are used to selectthe flexbody file type. The optional results recovery OUTPUT2 file can also becreated in this step for use in the results recovery solution in step 3.

The input file used in step 1 is similar to a standard SOL 103, but with theaddition of the MBDEXPORT case control command, and the DTI,UNITSbulk entry which is used to specify the system of units for the data stored inthe RFI or MNF files. If you choose to create the optional results recoveryOUTPUT2 file in this step, you should include RECVROP2=YES option onthe MBDEXPORT case control command, along with the following ASSIGNstatement in the file management section:

ASSIGN OUTPUT2=’name.out’ STATUS=UNKNOWN UNIT=20 FORM=UNFORM

For example, the input file to export an RFI would look similar to the following:

ASSIGN OUTPUT2=’results_recovery.out’ STATUS=UNKNOWN UNIT=20 FORM=UNFORM

Multi-body Dynamic Software Interfaces 7

ID NX Nastran, RFIREC00$ DESCRIPTION - RFI - RecurDyn RFI creation$ COMMENTS - The RFI created by this example will be ran through$ RecurDyn to generate an .mdf file.SOL 103TIME 10CENDTITLE = generate rfi and out files for RecurDyn stress recoveryMBDEXPORT RECURDYN FLEXBODY=YES,RECVROP2=YES,MINVAR=FULLECHO = NONEmethod=300disp = allstress = all$begin bulk$ Setting units for RecurDyndti,units,1,kg,n,m,s......

2. Flexbody Analysis in RecurDyn or ADAMS

The RFI or MNF created in step 1 is imported into RecurDyn or ADAMS,respectively, along with any other RFI’s or MNF’s which represent thecomponents of a multi-body assembly. The RecurDyn and ADAMS solutionsoutput the dynamic responses into a modal deformations file (MDF) in binaryformat (OUTPUT2), or in ASCII format (Punch).

3. Final NX Nastran SOL 103, results recovery

The MDF created by RecurDyn or ADAMS in step 2 is used in a final NXNastran SOL 103 solution to recover results, which can be used to evaluatethe stress condition on specific components of the assembly. The new casecontrol command MBDRECVR has been created to enter the needed recoveryoptions. If the optional results recovery OUTPUT2 file was computed in step 1,or created using the original dmap alter mnfx.alt, the resulting OUTPUT2 filecan be used in step 3. The following line in the file management section of theNX Nastran input file is required to reference the existing OUTPUT2 file:

ASSIGN INPUTT2=’<OUTPUT2_filename>’ UNIT=20

If no results recovery OUTPUT2 files exist, there is an option to recomputethem in the results recovery solution. It is more efficient to calculate them instep 1 and have the OUTPUT2 file ready for the results recovery step. See theMSRMODE option on the new MBDRECVR case control command below formore information on these options.

For example, the input file to recover results from RecurDyn dynamic resultsRFI would look similar to the following:

ASSIGN INPUTT2=’results_recovery.out’ UNIT=20 FORM=UNFORM$ DESCRIPTION - RFI - RecurDyn stress recoverySOL 103TIME 10

8 MBDEXPORTMulti-Body Dynamics Export

CEND$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$* CASE CONTROL$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*TITLE = recurdyn stress recovery from results_recovery.outMBDRECVR ASCII,CHECK=NOECHO = NONEmethod=300disp = allstress = allstrain = allforce = allbegin bulkinclude ’recurdyn_output.mdf’$ recurdyn requires following new UNITSdti,units,1,kg,n,m,s......

New MBDEXPORT Case Control Command

MBDEXPORT Multi-Body Dynamics Export

Generates interface file for third-party multi-body dynamics codes during a SOL103.

Format:

MBDEXPORT 9Multi-Body Dynamics Export

Interface Describers:

Describer Meaning

ADAMS Generate ADAMS Interface Modal Neutral File (MNF).

RECURDYN Generate RecurDyn Flex Input (RFI) file.

RECURDYN Example:

MBDEXPORT RECURDYN FLEXBODY=YES FLEXONLY=NO

RECURDYN Describers:

Describer Meaning

RECURDYN Generate RecurDyn Flex Input (RFI) file.

FLEXBODY Requests the generation of RFI (required).

NO Standard NX Nastran solution without RFI creation (default).

YES RFI generation requested.

FLEXONLY Determines if standard DMAP solution and data recovery runsor not after RFI creation is complete.

YES Only RFI creation occurs (default).

NO RFI file creation occurs along with standard DMAP solutionand data recovery.

MINVAR Determines how mass invariants are computed.

PARTIAL Mass invariants 6 and 8 are not computed.

CONSTANT Mass invariants 1,2,3 and 9 are computed.

FULL All nine mass invariants are computed.

NONE No mass invariants are computed.


Describer Meaning

PSETID Selects a set of elements defined in the OUTPUT(PLOT)(including PLOTEL) whose connectivity is exported to facegeometry into the RFI. (See Remark 16)

NONE No specific sets are selected, thus all grids, geometry andassociated modal data are written to RFI (default).

setid The connectivity of a specific element set is used to export facegeometry.

ALL The connectivity of all element sets are used to export facegeometry.

OUTGSTRS Determines if grid point stress is written to RFI.

NO Do not write grid point stress to RFI (default).

YES Write grid point stress to RFI.

OUTGSTRN Determines if grid point strain is written to RFI.

NO Do not write grid point strain to RFI (default).

YES Write grid point strain to RFI.

RECVROP2 Requests that the FLEXBODY run output an NX Nastran OP2file for use in post processing of RecurDyn/Flex results.

NO OP2 file will not be generated (default).

YES OP2 file will be generated.

CHECK Requests debug output be written to the f06 file whenRECVROP2=YES (See Remark 20).

NO No debug output will be written (default).

YES Debug output will be written.


RECURDYN Remarks:

1. The creation of the RecurDyn Flex Input file is applicable in a non-restart SOL103 analysis only. The RFI file naming convention is as follows: ‘jid_seid.rfi’,where seid is the integer number of the superelement (0 for residual-only run).The location of these files is the same directory as the jid.f06 file.

2. The creation of the RecurDyn Flex Input file is initiated by MBDEXPORTRECURDYN FLEXBODY=YES (other describers are optional) along with theinclusion of the bulk data entry DTI,UNITS.

3. The Data Table Input Bulk Data entry DTI,UNITS, which is required for anMBDEXPORT RECURDYN FLEXBODY=YES run, is used to specify the systemof units for the data stored in the RFI (unlike NX Nastran, RecurDyn is not aunitless code). Once identified, the units will apply to all superelements in themodel. The complete format is:

DTI UNITS 1 MASS FORCE LENGTH TIME

All entries are required. Acceptable character strings are listed below.

Mass:

KG - kilogram

LBM – pound-mass

SLUG – slug

GRAM – gram

OZM – ounce-mass

KLBM – kilo pound-mass (1000.lbm)

MGG – megagram

Force:

N – Newton

LBF – pound-force

KGF – kilograms-force

OZF – ounce-force

DYNE – dyne

KN – kilonewton

KLBF – kilo pound-force (1000.lbf)

MN - millinewton


Length:

KM – kilometer

M – meter

CM – centimeter

MM – millimeter

MI – mile

FT – foot

IN – inch

Time:

H – hour

MIN-minute

S – second

MS – millisecond

4. Since DTI,UNITS determines all units for the RFI, the units defined inWTMASS, which are important for units consistency in NX Nastran, are ignoredin the output to the RFI. For example, if the model mass is kilograms, force inNewtons, length in meters, and time in seconds, then WTMASS would equal 1ensuring that NX Nastran works with the consistent set of kg, N, and m. Theunits written to the RFI would be: “DTI,UNITS,1,KG,N,M,S”.

5. You can create flexible body attachment points by defining the component as asuperelement or part superelement, in which case the physical external (a-set)grids become the attachment points; or for a residual-only type model, you canuse standard NX Nastran ASET Bulk Data entries to define the attachmentpoints.

6. The eight mass variants are:


sp = [xyz]T are the coordinates of grid point p in the basic coordinate system.

fp=partitioned orthogonal modal matrix that corresponds to the translationaldegrees of freedom of grid p.

Ip=inertia tensor p.

fp*=partitioned orthogonal modal matrix that corresponds to the rotationaldegrees of freedom of grid p.

=skew-symmetric matrix formed for each grid translational degree offreedom for each mode.

M=number of modes.

N=number of grids.

7. To accurately capture the mode shapes when supplying SPOINT/QSETcombinations, the number of SPOINTS (ns) should be at least ns=n+(6+p),assuming that residual flexibility is on. In the above equation for ns, the numberof modes (n) is specified on the EIGR or EIGRL Bulk Data entries; the number ofload cases is p. In general, you can’t have too many SPOINTs, as excess ones willsimply be truncated with no performance penalty.


8. For FLEXBODY=YES runs, residual vectors for the component should always becalculated as they result in a more accurate representation of the componentshapes at little additional cost.

9. OMIT or OMIT1 Bulk Data entries are not supported.

10. Lumped mass formulation (default) is required. Either leavePARAM,COUPMASS out of the input file or supply PARAM,COUPMASS,-1(default) to ensure lumped mass.

11. P-elements are not allowed because they always use a coupled mass formulation.Likewise, the MFLUID fluid structure interface is not allowed because thevirtual mass matrix it generates is not diagonal.

12. PARAM,WTMASS,value with a value other than 1.0 may be used with an NXNastran run generating an RFI. It must have consistent units with regard tothe DTI,UNITS Bulk Data entry. Before generating the RFI, NX Nastran willappropriately scale the WTMASS from the physical mass matrix and modeshapes.

13. There is a distinction between how an MBDEXPORT RECURDYNFLEXBODY=YES run handles element-specific loads (such as a PLOAD4entry) versus those that are grid-specific (such as a FORCE entry), especiallywhen superelements are used. The superelement sees the total element-specificapplied load. For grid-specific loads, the loads attached to an external grid willmove downstream with the grid. That is to say, it is part of the boundary and notpart of the superelement. This distinction applies to a superelement run and notto a residual-only or parts superelement run.

14. The loads specified in NX Nastran generally fall into two categories: non-followeror fixed direction loads (non-circulatory) and follower loads (circulatory). Thefollower loads are nonconservative in nature. Examples of fixed direction loadsare the FORCE entry or a PLOAD4 entry when its direction is specified viadirection cosines. Examples of follower loads are the FORCE1 entry or thePLOAD4 entry when used to apply a normal pressure. By default in NXNastran, the follower loads are always active in SOL 103 and will result infollower stiffness being added to the differential stiffness and elastic stiffness ofthe structure. In a run with MBDEXPORT RECURDYN FLEXBODY=YES andsuperelements, if the follower force is associated with a grid description (such asa FORCE1) and the grid is external to the superelement, the follower load willmove downstream with the grid. Thus, the downstream follower contributionto the component’s stiffness will be lost, which could yield poor results. Thiscaution only applies to a superelement run and not to a residual-only or a partsuperelement run.


15. OUTGSTRS and OUTGSTRN entries require the use of standard NX NastranSTRESS= or STRAIN= used in conjunction with GPSTRESS= or GPSTRAIN=commands to produce grid point stress or strain. GPSTRESS(PLOT)= orGPSTRAIN(PLOT)= will suppress grid stress or strain print to the NX Nastran.f06 file.

16. To reduce the FE mesh detail for dynamic simulations, PSETID (on theMBDEXPORT Case Control command) defined with a SET entry is used todefine a set of PLOTELs or other elements used to select grids to display thecomponents in RecurDyn. This option can significantly reduce the size of theRFI without compromising accuracy in the FunctionBay simulation providingthat the mass invariant computation is requested. With superelement analysis,for any of these elements that lie entirely on the superelement boundary (all ofthe elements’ grids attached only to a-set or exterior grids), a SEELT Bulk Dataentry must be specified to keep that display element with the superelementcomponent. This can also be accomplished using PARAM, AUTOSEEL,YES. TheSEELT entry is not required with parts superelements, as boundary elementsstay with their component.

If the SET entry points to an existing set from the OUTPUT(PLOT) section, thissingle set is used explicitly to define elements used to select grids to display thecomponent in RecurDyn. If PSETID does not find the set ID in OUTPUT(PLOT),it will search sets in the case control for a matching set ID. This matching set IDlist then represents a list of OUTPUT(PLOT) defined elements’ sets, the union ofwhich will be used to define a set of PLOTELs or other elements used to selectgrids to display the component in RecurDyn. If the user wishes to select all ofthe sets in the OUTPUT(PLOT) section, then use PSETID=ALL.

The following element types are not supported for writing to an RFI, nor arethey supported as a ‘type’ entry in a set definition in OUTPUT(PLOT): CAABSF,CAEROi, CDUMi, CHACAB, CHACBR, CHBDYx, CDAMP3, CDAMP4,CELAS3, CELAS4, CFLUIDi, CMASS3, CMASS4, CRAC2D, CRAC3D,CTRMEM, CTWIST, CWEDGE, CWELD, and GENEL.

17. Typical NX Nastran data entry requirements are described below.

Typical Parameters:

• PARAM,RESVEC,character_value – controls calculation of residualflexibility (including inertia relief) modes. In SOL 103, residual flexibility ison by default for only component modes (o-set).

• PARAM,GRDPNT,value - mass invariants 1I, 2I, and 3I will be computedusing results of NX Nastran grid point weight generator execution in thebasic coordinate system.

Typical Case Control:


• MBDEXPORT RECURDYN FLEXBODY=YES is required for RFIgeneration.

• METHOD=n is required before or in the first subcase for modal solutions.

• SUPORT1=seid is necessary to select a static support set for a residualonly linear preload run.

• SUPER=n,SEALL=n is useful with multiple superelement models to selectan individual superelement as a flexible body. Cannot be used with a linearSTATSUB(PRELOAD) run.

• OUTPUT(PLOT) is necessary to define elements used to select grids todisplay the component in RecurDyn when PSETID=ALL or setid.

SET n=list of elements (including PLOTELs) is used to select grids todisplay the component.

• OUTPUT(POST) is necessary to define volume and surface for grid stressor strain shapes.

SET n=list is a list of elements for surface definition for grid stress or strainshapes.

Stress and strain data in the RFI is limited to the six components (i.e. 3normal and 3 shear) for a grid point for a given mode.

SURFACE n SET n NORMAL z3 is used to define a surface for writing stressand strain data. Only one FIBER selection is allowed for each SURFACE,thus the use of the FIBRE ALL keyword on the SURFACE case controlcommand will write stresses to the RFI at the Z1 fiber location only.

Since the FIBRE keyword only applies to stresses, strain data will always bewritten to the RFI at the MID location.

Stress and strain data at grid points can only be written to the RFI forsurface and volume type elements (e.g. CQUAD and CHEXA).

VOLUME n SET n is a volume definition.

The default SYSTEM BASIC is required with SURFACE or VOLUME.

• STRESS(PLOT) is necessary for stress shapes.

• STRAIN(PLOT) is necessary for strain shapes.

• GPSTRESS(PLOT) is necessary for grid point stress shapes to be includedin the RFI.


• GPSTRAIN(PLOT) is necessary for grid point strain shapes to be includedin the RFI.

Typical Bulk Data:

• DTI,UNITS,1,MASS,FORCE,LENGTH,TIME is required for RFI generation.For input files containing superelements, this command must reside in themain bulk data section.

• SPOINT,id_list defines and displays modal amplitude.

• SESET,SEID,grid_list defines a superelement (see GRID and BEGIN BULKSUPER=). The exterior grids will represent the attachment points alongwith the q-set.

• SEELT,SEID,element_list reassigns superelement boundary elements toan upstream superelement.

• RELEASE,SEID,C,Gi is an optional entry that removes DOFs from anattachment grid for which no constraint mode is desired. For example, thisallows the removal of rotational degrees of freedom from an analysis whereonly translational degrees of freedom are required.

• SEQSET,SEID,spoint_list defines modal amplitudes of a superelement (seeSEQSET1).

• SENQSET,SEID,N defines modal amplitudes of a part superelement. Itmust reside in the main Bulk Data Section.

• ASET,IDi,Ci defines attachment points for a residual-only run (see ASET1).

• QSET1,C,IDi defines modal amplitudes for the residual structure or modalamplitudes for a part superelement (see QSET).

• SUPORT1,SID,IDi,Ci defines the static support for a preload conditionwith a residual-only run. This entry is case control selectable. Do not useSUPORT.

• PLOTEL,EID,Gi can be used, along with existing model elements, to defineelements used to select grids to display the components in RecurDyn.

• EIGR,SID,METHOD,… obtains real eigenvalue extraction (see EIGRL).

18. MBDEXPORT and ADAMSMNF case control entries cannot be used in the sameanalysis run. In other words, a RecurDyn RFI file or an ADAMS MNF file can begenerated during a particular NX Nastran execution, but not both files at the


same time. Attempting to generate both files in the same analysis will cause anerror to be issued and the execution to be terminated.

19. The RECVROP2=YES option is used when you would like results recovery (usingthe MBDRECVR case control entry) from an RecurDyn/Flex analysis. Thisoption requires the following assignment command:

ASSIGN OUTPUT2=’name.out’ STATUS=UNKNOWN UNIT=20FORM=UNFORM

inserted into the file management section of the NX Nastran input file. It willcause an OP2 file with a .out extension to be generated, which then can beused as input into an NX Nastran SOL 103 run using the MBDRECVR casecontrol capability to perform results recovery from an RecurDyn/Flex analysis.FLEXBODY=YES is required with its use.

The data blocks output are:

MGGEW - physical mass external sort with weight mass removedMAAEW - modal massKAAE - modal stiffnessCMODEXT - component modes.

This capability is limited to no more than one superelement per NX Nastranmodel. Residual-only analyses are supported.

20. Setting CHECK=YES (which is only available when RECVROP2=YES) is notrecommended for models of realistic size due to the amount of data that willbe written to the f06.

21. The MBDEXPORT data routines use the environment variable TMPDIR fortemporary storage during the processing of mode shape data. As a result,TMPDIR must be defined when using MBDEXPORT. TMPDIR should equateto a directory string for temporary disk storage, preferably one with a largeamount of free space.

ADAMS Example:

MBDEXPORT ADAMS FLEXBODY=YES FLEXONLY=NO

ADAMS Describers:

Describer Meaning

ADAMS Generate ADAMS Interface Modal Neutral File (MNF).

FLEXBODY Requests the generation of MNF.


Describer Meaning

NO Standard NX Nastran solution without MNF creation (default).

YES MNF generation requested.

FLEXONLY Determines if standard DMAP solution runs or not after MNFcreation is complete.

YES Only MNF creation occurs (default).

NO MNF file creation occurs along with standard DMAP solution.

MINVAR Determines how mass invariants are computed.

PARTIAL Mass invariants 5 and 9 are not computed.

CONSTANT Mass invariants 1,2,6 and 7 are computed.

FULL All nine mass invariants are computed.

NONE No mass invariants are computed.

PSETID Selects a set of elements defined in the OUTPUT(PLOT) section(including PLOTEL) or on a sketch file whose connectivity isexported to face geometry to be used in ADAMS. (See Remark15)

NONE All grids, geometry and associated modal data is written toMNF (default).

setid The connectivity of a specific element set is used to export facegeometry.

ALL The connectivity of all element sets are used to export facegeometry.

sktunit The connectivity of element faces defined on a sketch file is usedto export face geometry. Note that the value must be a negativenumber to distinguish it from a setid value.

OUTGSTRS Determines if grid point stress is written to MNF.

NO Do not write grid point stress to MNF (default).


Describer Meaning

YES Write grid point stress to MNF.

OUTGSTRN Determines if grid point strain is written to MNF.

NO Do not write grid point strain to MNF (default).

YES Write grid point strain to MNF.

RECVROP2 Requests that the FLEXBODY run output an NX Nastran OP2file for use in post processing of ADAMS/Flex results.

NO OP2 file will not be generated (default).

YES OP2 file will be generated.

CHECK Requests debug output be written to the f06 file whenRECVROP2=YES (See Remark 18).



ADAMS Remarks:

1. The creation of the Adams MNF, which is applicable in a non-restart SOL103 analysis only, is initiated by MBDEXPORT ADAMS FLEXBODY=YES(other describers are optional) along with the inclusion of the bulk data entryDTI,UNITS. The MNF file naming convention is as follows: ‘jid_seid.mnf’, whereseid is the integer number of the superelement (0 for residual-only run). Thelocation of these files is the same directory as the jid.f06 file.

2. The Data Table Input Bulk Data entry DTI,UNITS, which is required for anMBDEXPORT ADAMS FLEXBODY=YES run, is used to specify the systemof units for the data stored in the MNF (unlike NX Nastran, ADAMS is not aunitless code). Once identified, the units will apply to all superelements in themodel. The complete format is:

DTI UNITS 1 MASS FORCE LENGTH TIME

All entries are required. Acceptable character strings are listed below.

Mass:

KG - kilogram


LBM – pound-mass (0.45359237 kg)

SLUG – slug (14.5939029372 kg)

GRAM – gram (1E-3 kg)

OZM – ounce-mass (0.02834952 kg)

KLBM – kilo pound-mass (1000 lbm) (453.59237 kg)

MGG – megagram (1E3 kg)

MG – milligram (1E-6 kg)

MCG – microgram (1E-9 kg)

NG – nanogram (1E-12 kg)

UTON – U.S. ton (907.18474 kg)

SLI – slinch (175.1271524 kg)

Force:

N – Newton

LBF – pound-force (4.44822161526 N)

KGF – kilograms-force (9.80665 N)

OZF – ounce-force (0.2780139 N)

DYNE – dyne (1E-5 N)

KN – kilonewton (1E3 N)

KLBF – kilo pound-force (1000 lbf) (4448.22161526 N)

MN – millinewton (1E-3 N)

MCN – micronewton (1E-6 N)

NN – nanonewton (1E-9 N)

Length:

M – meter

KM – kilometer (1E3 m)

CM – centimeter (1E-2 m)

MM – millimeter (1E-3 m)

MI – mile (1609.344 m)

FT – foot (0.3048 m)


IN – inch (25.4E-3 m)

MCM – micrometer (1E-6 m)

NM – nanometer (1E-9 m)

A – Angstrom (1E-10 m)

YD – yard (0.9144 m)

ML – mil (25.4E-6 m)

MCI – microinch (25.4E-9 m)

Time:

S – second

H – hour (3600.0 sec)

MIN-minute (60.0 sec)

MS – millisecond (1E-3 sec)

MCS – microsecond (1E-6 sec)

NS – nanosecond (1E-9 sec)

D – day (86.4E3 sec)

3. Since DTI,UNITS determines all units for the MNF, the units defined inWTMASS, which are important for units consistency in NX Nastran, are ignoredin the output to the MNF. For example, if the model mass is kilograms, force inNewtons, length in meters, and time in seconds, then WTMASS would equal 1ensuring that NX Nastran works with the consistent set of kg, N, and m. Theunits written to the MNF would be: “DTI,UNITS,1,KG,N,M,S”.

4. You can create flexible body attachment points by defining the component as asuperelement or part superelement, in which case the physical external (a-set)grids become the attachment points; or for a residual-only type model, you canuse standard NX Nastran ASET Bulk Data entries to define the attachmentpoints.

5. The nine mass variants are:


sp = [xyz]T are the coordinates of grid point p in the basic coordinate system.


fp=partitioned orthogonal modal matrix that corresponds to the translationaldegrees of freedom of grid p.

Ip=inertia tensor p.

fp*=partitioned orthogonal modal matrix that corresponds to the rotationaldegrees of freedom of grid p.

=skew-symmetric matrix formed for each grid translational degree offreedom for each mode.

M=number of modes.

N=number of grids.

6. To accurately capture the mode shapes when supplying SPOINT/QSETcombinations, the number of SPOINTS (ns) should be at least ns=n+(6+p),assuming that residual flexibility is on. In the above equation for ns, the numberof modes (n) is specified on the EIGR or EIGRL Bulk Data entries; the number ofload cases is p. In general, you can’t have too many SPOINTs, as excess ones willsimply be truncated with no performance penalty.

7. For FLEXBODY=YES runs, residual vectors for the component should always becalculated as they result in a more accurate representation of the componentshapes at little additional cost.

8. OMIT or OMIT1 Bulk Data entries are not supported.

9. Lumped mass formulation (default) is required. Either leavePARAM,COUPMASS out of the input file or supply PARAM,COUPMASS,-1(default) to ensure lumped mass.

10. P-elements are not allowed because they always use a coupled mass formulation.Likewise, the MFLUID fluid structure interface is not allowed because thevirtual mass matrix it generates is not diagonal.

11. PARAM,WTMASS,value with a value other than 1.0 may be used with an NXNastran run generating an MNF. It must have consistent units with regardto the DTI,UNITS Bulk Data entry. Before generating the MNF, NX Nastranwill appropriately scale the WTMASS from the physical mass matrix and modeshapes.


12. There is a distinction between how an MBDEXPORT ADAMS FLEXBODY=YESrun handles element-specific loads (such as a PLOAD4 entry) versus thosethat are grid-specific (such as a FORCE entry), especially when superelementsare used. The superelement sees the total element-specific applied load. Forgrid-specific loads, the loads attached to an external grid will move downstreamwith the grid. That is to say, it is part of the boundary and not part of thesuperelement. This distinction applies to a superelement run and not to aresidual-only or parts superelement run.

13. The loads specified in NX Nastran generally fall into two categories: non-followeror fixed direction loads (non-circulatory) and follower loads (circulatory). Thefollower loads are nonconservative in nature. Examples of fixed direction loadsare the FORCE entry or a PLOAD4 entry when its direction is specified viadirection cosines. Examples of follower loads are the FORCE1 entry or thePLOAD4 entry when used to apply a normal pressure. By default in NXNastran, the follower loads are always active in SOL 103 and will result infollower stiffness being added to the differential stiffness and elastic stiffnessof the structure. In a run with MBDEXPORT ADAMS FLEXBODY=YES andsuperelements, if the follower force is associated with a grid description (such asa FORCE1) and the grid is external to the superelement, the follower load willmove downstream with the grid. Thus, the downstream follower contributionto the component’s stiffness will be lost, which could yield poor results. Thiscaution only applies to a superelement run and not to a residual-only or a partsuperelement run.

14. OUTGSTRS and OUTGSTRN entries require the use of standard NX NastranSTRESS= or STRAIN= used in conjunction with GPSTRESS= or GPSTRAIN=commands to produce grid point stress or strain. GPSTRESS(PLOT)= orGPSTRAIN(PLOT)= will suppress grid stress or strain print to the NX Nastran.f06 file.

15. To reduce the FE mesh detail for dynamic simulations, PSETID (on theMBDEXPORT Case Control command) defined with a SET entry (i.e. setid) isused to define a set of PLOTELs or other elements used to select grids to displaythe components in ADAMS. This option can significantly reduce the size of theMNF without compromising accuracy in the ADAMS simulation providing thatthe mass invariant computation is requested. With superelement analysis, forany of these elements that lie entirely on the superelement boundary (all of theelements’ grids attached only to a-set or exterior grids), a SEELT Bulk Dataentry must be specified to keep that display element with the superelementcomponent. This can also be accomplished using PARAM, AUTOSEEL,YES. TheSEELT entry is not required with parts superelements, as boundary elementsstay with their component.

If the SET entry points to an existing set from the OUTPUT(PLOT) section, thissingle set is used explicitly to define elements used to select grids to display the


component in ADAMS. If PSETID does not find the set ID in OUTPUT(PLOT), itwill search sets in the case control for a matching set ID. This matching set IDlist then represents a list of OUTPUT(PLOT) defined elements’ sets, the union ofwhich will be used to define a set of PLOTELs or other elements used to selectgrids to display the component in ADAMS. If the user wishes to select all of thesets in the OUTPUT(PLOT) section, then use PSETID=ALL.

The following element types are not supported for writing to an MNF, nor arethey supported as a ‘type’ entry in a set definition in OUTPUT(PLOT): CAABSF,CAEROi, CDUMi, CHACAB, CHACBR, CHBDYx, CDAMP3, CDAMP4,CELAS3, CELAS4, CFLUIDi, CMASS3, CMASS4, CRAC2D, CRAC3D,CTRMEM, CTWIST, CWEDGE, CWELD, and GENEL.

PSETID can also point to a sketch file using PSETID=-sktunit, where sktunitreferences an ASSIGN statement of the form

ASSIGN SKT=‘sketch_file.dat’,UNIT=sktunit.

The grids defined for the elements’ faces in the sketch file, along with all external(i.e. boundary) grids for the superelements, will be the only grids (and theirassociated data) written to the MNF.

The format of the sketch file, which describes the mesh as a collection of faces,must be as follows:

face_countface_1_node_count face_1_nodeid_1 face_1_nodeid_2 ...face_2_node_count face_2_nodeid_1 face_2_nodeid_2 ...<etc>

Faces must have a node count of at least two. For example, a mesh comprised ofa single brick element might be described as follows:

64 1000 1001 1002 10034 1007 1006 1005 10044 1000 1004 1005 10014 1001 1005 1006 10024 1002 1006 1007 10034 1003 1007 1004 1000

Alternatively, the mesh might be described as a stick figure using a collection oflines (two node faces), as shown below:

82 101 1022 102 1032 103 1042 104 1052 105 1062 106 1072 107 1082 108 109


16. Typical NX Nastran data entry requirements are described below.

Typical Parameters:

• PARAM,RESVEC,character_value – controls calculation of residualflexibility (including inertia relief) modes. In SOL 103, residual flexibility ison by default for only component modes (o-set).

• PARAM,GRDPNT, value - mass invariants 1I, 2I, and 7I will be computedusing results of NX Nastran grid point weight generator execution in thebasic coordinate system.

Typical Case Control:

• MBDEXPORT ADAMS FLEXBODY=YES is required for MNF generation.

• METHOD=n is required before or in the first subcase for modal solutions.

• SUPORT1=seid is necessary to select a static support set for a residualonly linear preload run.

• SUPER=n,SEALL=n is useful with multiple superelement models to selectan individual superelement as a flexible body. Cannot be used with a linearSTATSUB(PRELOAD) run.

• OUTPUT(PLOT) is necessary to define elements used to select grids todisplay the component in ADAMS when PSETID=ALL or setid.

SET n=list of elements (including PLOTELs) is used to select grids todisplay the component.

• OUTPUT(POST) is necessary to define volume and surface for grid stressor strain shapes.

SET n=list is a list of elements for surface definition for grid stress or strainshapes.

Stress and strain data in the MNF is limited to the six components (i.e. 3normal and 3 shear) for a grid point for a given mode.

SURFACE n SET n NORMAL z3 is used to define a surface for writing stressand strain data. Only one FIBER selection is allowed for each SURFACE,thus the use of the FIBRE ALL keyword on the SURFACE case controlcommand will write stresses to the MNF at the Z1 fiber location only.

Since the FIBRE keyword only applies to stresses, strain data will always bewritten to the MNF at the MID location.

Stress and strain data at grid points can only be written to the MNF forsurface and volume type elements (e.g. CQUAD and CHEXA).


VOLUME n SET n is a volume definition.

The default SYSTEM BASIC is required with SURFACE or VOLUME.

• STRESS(PLOT) is necessary for stress shapes.

• STRAIN(PLOT) is necessary for strain shapes.

• GPSTRESS(PLOT) is necessary for grid point stress shapes to be includedin the MNF.

• GPSTRAIN(PLOT) is necessary for grid point strain shapes to be includedin the MNF.

Typical Bulk Data:

• DTI,UNITS,1,MASS,FORCE,LENGTH,TIME is required for MNFgeneration. For input files containing superelements, this command mustreside in the main bulk data section.

• SPOINT,id_list defines and displays modal amplitude.SESET,SEID,grid_listdefines a superelement (see GRID and BEGIN BULK SUPER=). Theexterior grids will represent the attachment points along with the q-set.

• SEELT,SEID,element_list reassigns superelement boundary elements toan upstream superelement.

• RELEASE,SEID,C,Gi is an optional entry that removes DOFs from anattachment grid for which no constraint mode is desired. For example, thisallows the removal of rotational degrees of freedom from an analysis whereonly translational degrees of freedom are required.

• SEQSET,SEID,spoint_list defines modal amplitudes of a superelement (seeSEQSET1).

• SENQSET,SEID,N defines modal amplitudes of a part superelement. Itmust reside in the main Bulk Data Section.

• ASET,IDi,Ci defines attachment points for a residual-only run (see ASET1).

• QSET1,C,IDi defines modal amplitudes for the residual structure or modalamplitudes for a part superelement (see QSET).

• SUPORT1,SID,IDi,Ci defines the static support for a preload conditionwith a residual-only run. This entry is case control selectable. Do not useSUPORT.


• PLOTEL,EID,Gi can be used, along with existing model elements, to defineelements used to select grids to display the components in ADAMS.

• EIGR,SID,METHOD,… obtains real eigenvalue extraction (see EIGRL).

17. The RECVROP2=YES option is used when you would like results recovery (usingthe MBDRECVR case control entry) from an ADAMS/Flex analysis. This optionrequires the following assignment command:

ASSIGN OUTPUT2=’name.out’ STATUS=UNKNOWN UNIT=20FORM=UNFORM

inserted into the file management section of the NX Nastran input file. It willcause an OP2 file with a .out extension to be generated, which then can beused as input into an NX Nastran SOL 103 run using the MBDRECVR casecontrol capability to perform results recovery from an ADAMS/Flex analysis.FLEXBODY=YES is required with its use.

The data blocks output are:

MGGEW - physical mass external sort with weight mass removedMAAEW - modal massKAAE - modal stiffnessCMODEXT - component modes.

This capability is limited to no more than one superelement per NX Nastranmodel. Residual-only analyses are supported.

18. Setting CHECK=YES (which is only available when RECVROP2=YES) is notrecommended for models of realistic size due to the amount of data that willbe written to the f06.

19. The MBDEXPORT data routines use the environment variable TMPDIR fortemporary storage during the processing of mode shape data. As a result,TMPDIR must be defined when using MBDEXPORT. TMPDIR should equateto a directory string for temporary disk storage, preferably one with a largeamount of free space.

20. If any damping is defined in the model, an equivalent modal viscous dampingwill be determined for each mode and written to the MNF. This equivalent modalviscous damping is defined as:

= yTBey

30 MBDRECVRMulti-Body Dynamics Results Recovery

where d = equivalent modal viscous dampingy = mode shapesBe = equivalent viscous damping defined by:

G, W3, and W4 are parameters described in the “Parameter Descriptions” sectionof this guide.

New MBDRECVR Case Control Command

MBDRECVR Multi-Body Dynamics Results Recovery

Imports required files from third-party multi-body dynamics codes to performresults recovery.

Format:

Examples:

RecurDyn Example:

ASSIGN INPUTT2=‘rfi_results.mdf’ UNIT=13...CENDSTRESS(PLOT)=100MBDRECVR

ADAMS Example:

ASSIGN INPUTT2=‘adams_results.mdf’ UNIT=13...CENDSTRESS(PLOT)=100MBDRECVR

MBDRECVR 31Multi-Body Dynamics Results Recovery

Describers:

Describer Meaning

BINARY OUTPUT2 file format for RecurDyn or ADAMS modaldeformations file (default). (See Remarks 1 and 2)

ASCII PUNCH file format for RecurDyn or ADAMS modaldeformations file. (See Remarks 1 and 2).

MSRMODE Specifies stress recovery type (see remarks 6 and 7).

0 Component definitions are stored in an OUTPUT2 file(specifically, an *.out file created by using RECVROP2=YES onthe MBDEXPORT ADAMS or RECURDYN case control in apre-ADAMS/Flex or RecurDyn, respectively, NX Nastran run.The OUTPUT2 files used in this case do not contain data blocksused for MNF or RFI creation (default).

1 Same as option 0, except that the OUTPUT2 file will contain10 additional data blocks used for RFI or MNF creation bya RecurDyn or ADAMS pre-processor (specifically, a *.out filecreated through use of the mnfx.alt DMAP alter capability).

2 No file reference (specifically, component definitions will berecomputed)

RGBODY Requests the addition of rigid body motion with modaldeformations (see remark 5).

NO Do not include rigid body motion (default).

YES Include rigid body motion.

MSGLVL Level of diagnostic output from Lanczos eigensolver whencomponent definitions are determined (applies only whenMSRMODE=2).

0 No output (default).

1 Warning and fatal messages.

2 Summary output.

3 Detailed output on cost and convergence.


Describer Meaning

4 Detailed output on orthogonalization.

CHECK Requests debug output be written to the f06 file (See Remark 9).



Remarks:

1. When modal deformations to be read are in binary (OUTPUT2) format(specifically, BINARY), the following statement needs to be specified near the topof the NX Nastran input file in the file management section:

ASSIGN INPUTT2=‘<MDFilename>’ UNIT=13

where <MDFilename> is the name of the modal deformations file from ADAMSor RecurDyn.

2. To input the modal deformations file from ADAMS or RecurDyn in ASCII(Punch) format (specifically, ASCII), the following statement needs to be includedin the bulk data section:

INCLUDE ‘<MDFilename>’ where ‘<MDFilename>’ is the name of the modaldeformations file.

3. Dynamic stress/strain output can either be in .f06, PUNCH, and/or OUTPUT2according to standard NX Nastran functionality. However, stress recovery in NXNastran from ADAMS or RecurDyn results do not support XYPLOT output.

4. If displacements, stresses, and/or strains are to be available for post processing,one or more of the following statements must appear in the case control sectionof the NX Nastran input file:

DISP(PLOT) = <set id>

STRAIN(FIBER,PLOT) = <set id>

STRESS(PLOT) = <set id>

5. Rigid body motions from an ADAMS or RecurDyn simulation are included in themodal deformations file, but they are not applied unless the RGBODY keywordis set to YES and the SORT1 option is included in the DISP(PLOT) command incase control. Including rigid body motion affects the display and animation ofthe flexible component, but it has no effect on dynamic stresses.


6. For MSRMODE=0 or 1, stress recovery references the OUTPUT2 fileobtained from the initial CMS analysis (specifically, RECVROP2=YES on theMBDEXPORT ADAMS or RECURDYN case control entry or use of the mnfx.alt(ADAMS only) DMAP alter capability). No other files are required. Thegeometric data needs to be included in the bulk data of the NX Nastran inputfile because geometry is missing from the OUTPUT2 file. This mode of stressrecovery is faster than the MSRMODE=2 mode. To reference this OUTPUT2file the following line needs to be included in the file specification section of theNX Nastran input file:

ASSIGN INPUTT2=‘<OUTPUT2_filename>’ UNIT=20

7. For MSRMODE=2, no files are referenced for stress recovery. Instead, a fullCMS reanalysis is performed to build the reference data for the stress recoveryanalysis. Obviously, the analysis time is significantly far greater compared tothe MSRMODE=0 or 1 method, but this method frees up disk space. There isalso risk in using this method. If the reanalysis generates slightly differentcomponent eigenvalues or eigenvectors than were generated during the creationof the ADAMS MNF or RecurDyn RFI in the initial NX Nastran run, thenthe ADAMS or RecurDyn results in the MDF (modal deformation file) will beinconsistent and incorrect results will be recovered. Something as simple as asign change for one eigenvector will cause incorrect results to be recovered. It is,therefore, highly recommended that MSRMODE=0 or 1 always be used.

8. This capability must be performed in SOL 103 and is limited to no more thanone superelement per NX Nastran model. Residual-only analyses are supported.

9. Setting CHECK=YES is not recommended for models of realistic size due to theamount of data that will be written to the f06.


Example Input Files

RecurDyn RFI Creation Solution

ASSIGN OUTPUT2=’rfirec00.out’ STATUS=UNKNOWN UNIT=20 FORM=UNFORMID NX Nastran, RFIREC00$$ DESCRIPTION - RFI - RecurDyn stress recovery - initial run to create$ .out and .rfi files for subsequent recovery runs$$ COMMENTS - The RFI created by this test case MUST be run through RecurDyn$ in order to generate an .mdf file.$SOL 103TIME 10CENDTITLE = generate rfi and out files for RecurDyn stress recoveryMBDEXPORT RECURDYN FLEXBODY=YES,RECVROP2=YES,MINVAR=FULLECHO = NONEmethod=300disp = allstress = all$begin bulk$$ RecurDyn requires following new UNITS card$dti,units,1,kg,n,m,s$$ turn on gridpoint weight generator$param,grdpnt,0$$ default value - RecurDyn must use the above units$param,wtmass,1.0$$ select number of modes$eigr 300 lan 10$$ define interior grids as superelement 2$ the corner grids 1, 11, 111, 121 are the exterior$ or attachment point grids$seset,2,2,thru,10seset,2,12,thru,110seset,2,112,thru,120$$ scalar point and seqset1 to define dofs to use for component modes$spoint,80001,thru,80018seqset1,2,0,80001,thru,80018$$ define plotels$plotel,10001,1,12plotel,10002,12,121plotel,10003,121,111plotel,10004,111,1plotel,10006,2,10


plotel,10007,22,110plotel,10008,120,112plotel,10009,12,100$$ seelt to put element 1003 and 1004 into se 2$seelt,2,10003,10004$$ start grid specs$grid, 1,, 0.0, 0.0, 0.0=,*11,,*.10,===9grid, 2,, 0.0, 0.1, 0.0=,*11,,*.10,===9grid, 3,, 0.0, 0.2, 0.0=,*11,,*.10,===9grid, 4,, 0.0, 0.3, 0.0=,*11,,*.10,===9grid, 5,, 0.0, 0.4, 0.0=,*11,,*.10,===9grid, 6,, 0.0, 0.5, 0.0=,*11,,*.10,===9grid, 7,, 0.0, 0.6, 0.0=,*11,,*.10,===9grid, 8,, 0.0, 0.7, 0.0=,*11,,*.10,===9grid, 9,, 0.0, 0.8, 0.0=,*11,,*.10,===9grid, 10,, 0.0, 0.9, 0.0=,*11,,*.10,===9grid, 11,, 0.0, 1.0, 0.0=,*11,,*.10,===9$$ start element specs$cquadr, 1,1,1,2,13,12=,*1,=,*11,*11,*11,*11=8cquadr, 11,1,2,3,14,13=,*1,=,*11,*11,*11,*11=8cquadr, 21,1,3,4,15,14=,*1,=,*11,*11,*11,*11=8cquadr, 31,1,4,5,16,15=,*1,=,*11,*11,*11,*11=8cquadr, 41,1,5,6,17,16=,*1,=,*11,*11,*11,*11=8


cquadr, 51,1,6,7,18,17=,*1,=,*11,*11,*11,*11=8cquadr, 61,1,7,8,19,18=,*1,=,*11,*11,*11,*11=8cquadr, 71,1,8,9,20,19=,*1,=,*11,*11,*11,*11=8cquadr, 81,1,9,10,21,20=,*1,=,*11,*11,*11,*11=8cquadr, 91,1,10,11,22,21=,*1,=,*11,*11,*11,*11=8conm2,1001,2,0,1.0$$ element properties input$pshell,1,1,0.01,1$$ material properties input$mat1,1,.2223+12,.0855+12,0.3,7803.0$enddata

Results Recovery Using RecurDyn *.mdf Output

ASSIGN INPUTT2=’rfirec00.out’ UNIT=20 FORM=UNFORMID NX Nastran, RFIREC02$$ DESCRIPTION - RFI - RecurDyn stress recovery$SOL 103TIME 10CEND$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*$* CASE CONTROL$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*TITLE = recurdyn stress recovery from rfirec00MBDRECVR ASCII,CHECK=NOECHO = NONEmethod=300$disp = allstress = allstrain = allforce = all$begin bulk$include ’rfirec00.mdf’$$ recurdyn requires following new UNITS card$


dti,units,1,kg,n,m,s$$ turn on gridpoint weight generator$param,grdpnt,0$$ default value - recurdyn must use the above units$param,wtmass,1.0$$ select number of modes$eigr 300 lan 10$$ define interior grids as superelement 2$ the corner grids 1, 11, 111, 121 are the exterior$ or attachment point grids$seset,2,2,thru,10seset,2,12,thru,110seset,2,112,thru,120$$ scalar point and seqset1 to define dofs to use for component modes$spoint,80001,thru,80018seqset1,2,0,80001,thru,80018$$ define plotels$plotel,10001,1,12plotel,10002,12,121plotel,10003,121,111plotel,10004,111,1plotel,10006,2,10plotel,10007,22,110plotel,10008,120,112plotel,10009,12,100$$ seelt to put element 1003 and 1004 into se 2$seelt,2,10003,10004$$ start grid specs$grid, 1,, 0.0, 0.0, 0.0=,*11,,*.10,===9grid, 2,, 0.0, 0.1, 0.0=,*11,,*.10,===9grid, 3,, 0.0, 0.2, 0.0=,*11,,*.10,===9grid, 4,, 0.0, 0.3, 0.0=,*11,,*.10,===9grid, 5,, 0.0, 0.4, 0.0=,*11,,*.10,===9grid, 6,, 0.0, 0.5, 0.0=,*11,,*.10,==


=9grid, 7,, 0.0, 0.6, 0.0=,*11,,*.10,===9grid, 8,, 0.0, 0.7, 0.0=,*11,,*.10,===9grid, 9,, 0.0, 0.8, 0.0=,*11,,*.10,===9grid, 10,, 0.0, 0.9, 0.0=,*11,,*.10,===9grid, 11,, 0.0, 1.0, 0.0=,*11,,*.10,===9$$ start element specs$cquadr, 1,1,1,2,13,12=,*1,=,*11,*11,*11,*11=8cquadr, 11,1,2,3,14,13=,*1,=,*11,*11,*11,*11=8cquadr, 21,1,3,4,15,14=,*1,=,*11,*11,*11,*11=8cquadr, 31,1,4,5,16,15=,*1,=,*11,*11,*11,*11=8cquadr, 41,1,5,6,17,16=,*1,=,*11,*11,*11,*11=8cquadr, 51,1,6,7,18,17=,*1,=,*11,*11,*11,*11=8cquadr, 61,1,7,8,19,18=,*1,=,*11,*11,*11,*11=8cquadr, 71,1,8,9,20,19=,*1,=,*11,*11,*11,*11=8cquadr, 81,1,9,10,21,20=,*1,=,*11,*11,*11,*11=8cquadr, 91,1,10,11,22,21=,*1,=,*11,*11,*11,*11=8conm2,1001,2,0,1.0$$ element properties input$pshell,1,1,0.01,1$$ material properties input$mat1,1,.2223+12,.0855+12,0.3,7803.0$enddata


ADAMS MNF Creation Solution

ASSIGN OUTPUT2=’mnfrec00.out’ STATUS=UNKNOWN UNIT=20 FORM=UNFORMID NX Nastran, MNFREC00$$ DESCRIPTION - MNF - ADAMS stress recovery - initial run to create$ .out and .mnf files for subsequent recovery runs$$ COMMENTS - The MNF created by this test case MUST be run through ADAMS$ in order to generate an .mdf file.$SOL 103TIME 10CENDTITLE = generate mnf and out files for adams stress recoveryMBDEXPORT ADAMS FLEXBODY=YES,RECVROP2=YES,MINVAR=FULLECHO = NONEmethod=300disp = allstress = all$begin bulk$$ ADAMS requires following new UNITS card$dti,units,1,kg,n,m,s$$ turn on gridpoint weight generator$param,grdpnt,0$$ default value - ADAMS must use the above units$param,wtmass,1.0$$ select number of modes$eigr 300 lan 10$$ define interior grids as superelement 2$ the corner grids 1, 11, 111, 121 are the exterior$ or attachment point grids$seset,2,2,thru,10seset,2,12,thru,110seset,2,112,thru,120$$ scalar point and seqset1 to define dofs to use for component modes$spoint,80001,thru,80018seqset1,2,0,80001,thru,80018$$ define plotels$plotel,10001,1,12plotel,10002,12,121plotel,10003,121,111plotel,10004,111,1plotel,10006,2,10plotel,10007,22,110plotel,10008,120,112


plotel,10009,12,100$$ seelt to put element 1003 and 1004 into se 2$seelt,2,10003,10004$$ start grid specs$grid, 1,, 0.0, 0.0, 0.0=,*11,,*.10,===9grid, 2,, 0.0, 0.1, 0.0=,*11,,*.10,===9grid, 3,, 0.0, 0.2, 0.0=,*11,,*.10,===9grid, 4,, 0.0, 0.3, 0.0=,*11,,*.10,===9grid, 5,, 0.0, 0.4, 0.0=,*11,,*.10,===9grid, 6,, 0.0, 0.5, 0.0=,*11,,*.10,===9grid, 7,, 0.0, 0.6, 0.0=,*11,,*.10,===9grid, 8,, 0.0, 0.7, 0.0=,*11,,*.10,===9grid, 9,, 0.0, 0.8, 0.0=,*11,,*.10,===9grid, 10,, 0.0, 0.9, 0.0=,*11,,*.10,===9grid, 11,, 0.0, 1.0, 0.0=,*11,,*.10,===9$$ start element specs$cquadr, 1,1,1,2,13,12=,*1,=,*11,*11,*11,*11=8cquadr, 11,1,2,3,14,13=,*1,=,*11,*11,*11,*11=8cquadr, 21,1,3,4,15,14=,*1,=,*11,*11,*11,*11=8cquadr, 31,1,4,5,16,15=,*1,=,*11,*11,*11,*11=8cquadr, 41,1,5,6,17,16=,*1,=,*11,*11,*11,*11=8cquadr, 51,1,6,7,18,17=,*1,=,*11,*11,*11,*11


=8cquadr, 61,1,7,8,19,18=,*1,=,*11,*11,*11,*11=8cquadr, 71,1,8,9,20,19=,*1,=,*11,*11,*11,*11=8cquadr, 81,1,9,10,21,20=,*1,=,*11,*11,*11,*11=8cquadr, 91,1,10,11,22,21=,*1,=,*11,*11,*11,*11=8conm2,1001,2,0,1.0$$ element properties input$pshell,1,1,0.01,1$$ material properties input$mat1,1,.2223+12,.0855+12,0.3,7803.0$enddata

Results Recovery Using ADAMS *.mdf Output

ASSIGN INPUTT2=’mnfrec00.out’ UNIT=20 FORM=UNFORMID NX Nastran, MNFREC02$$ DESCRIPTION - MNF - ADAMS stress recovery$SOL 103TIME 10CEND$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*$* CASE CONTROL$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*TITLE = adams stress recovery from mnfrec00MBDRECVR ASCII,CHECK=NOECHO = NONEmethod=300$disp = allstress = allstrain = allforce = all$begin bulk$include ’mnfrec00.mdf’$$ ADAMS requires following new UNITS card$dti,units,1,kg,n,m,s$


$ turn on gridpoint weight generator$param,grdpnt,0$$ default value - ADAMS must use the above units$param,wtmass,1.0$$ select number of modes$eigr 300 lan 10$$ define interior grids as superelement 2$ the corner grids 1, 11, 111, 121 are the exterior$ or attachment point grids$seset,2,2,thru,10seset,2,12,thru,110seset,2,112,thru,120$$ scalar point and seqset1 to define dofs to use for component modes$spoint,80001,thru,80018seqset1,2,0,80001,thru,80018$$ define plotels$plotel,10001,1,12plotel,10002,12,121plotel,10003,121,111plotel,10004,111,1plotel,10006,2,10plotel,10007,22,110plotel,10008,120,112plotel,10009,12,100$$ seelt to put element 1003 and 1004 into se 2$seelt,2,10003,10004$$ start grid specs$grid, 1,, 0.0, 0.0, 0.0=,*11,,*.10,===9grid, 2,, 0.0, 0.1, 0.0=,*11,,*.10,===9grid, 3,, 0.0, 0.2, 0.0=,*11,,*.10,===9grid, 4,, 0.0, 0.3, 0.0=,*11,,*.10,===9grid, 5,, 0.0, 0.4, 0.0=,*11,,*.10,===9grid, 6,, 0.0, 0.5, 0.0=,*11,,*.10,===9grid, 7,, 0.0, 0.6, 0.0


=,*11,,*.10,===9grid, 8,, 0.0, 0.7, 0.0=,*11,,*.10,===9grid, 9,, 0.0, 0.8, 0.0=,*11,,*.10,===9grid, 10,, 0.0, 0.9, 0.0=,*11,,*.10,===9grid, 11,, 0.0, 1.0, 0.0=,*11,,*.10,===9$$ start element specs$cquadr, 1,1,1,2,13,12=,*1,=,*11,*11,*11,*11=8cquadr, 11,1,2,3,14,13=,*1,=,*11,*11,*11,*11=8cquadr, 21,1,3,4,15,14=,*1,=,*11,*11,*11,*11=8cquadr, 31,1,4,5,16,15=,*1,=,*11,*11,*11,*11=8cquadr, 41,1,5,6,17,16=,*1,=,*11,*11,*11,*11=8cquadr, 51,1,6,7,18,17=,*1,=,*11,*11,*11,*11=8cquadr, 61,1,7,8,19,18=,*1,=,*11,*11,*11,*11=8cquadr, 71,1,8,9,20,19=,*1,=,*11,*11,*11,*11=8cquadr, 81,1,9,10,21,20=,*1,=,*11,*11,*11,*11=8cquadr, 91,1,10,11,22,21=,*1,=,*11,*11,*11,*11=8conm2,1001,2,0,1.0$$ element properties input$pshell,1,1,0.01,1$$ material properties input$mat1,1,.2223+12,.0855+12,0.3,7803.0$enddata

44 Rotor Dynamics

2.2 Rotor DynamicsThe NX Nastran rotor dynamics capability lets you predict the dynamic behaviorof rotating systems. Rotating systems include additional forces that are notpresent in non-rotating systems. These additional forces are a function of therotational speed and result in modal frequencies that vary with the speed ofrotation. Rotational speeds that are equal to a modal frequency are consideredcritical speeds. Since critical speeds can cause instability in the rotating system tothe point of a catastrophic failure, predicting them is extremely important.

The typical rotor dynamics process is to

• Use the results of a complex eigenvalue analysis (SOL 110 - Model ComplexEigenvalue analysis) to plot Campbell Diagrams and determine whirlfrequencies and critical speeds.

• Compute the response of the rotating system in frequency domain (SOL 111 –Modal Frequency Response Analysis) and correlate with the critical speedsdetermined from the Campbell Diagrams.

This process has been improved with the following enhancements.

• Modal Transient Response Analysis (SOL 112) is now supported. A transientresponse analysis captures the dynamic response of events in which therotational speed is changing, for example, during the startup of a turbineengine.

• You can scale the speed of each rotor included on the ROTORD bulk entryusing the RSPEED field. Systems with multiple rotors rotating at differentspeeds can now be analyzed. The scaled rotor speed influences both thecomplex modal solution, and the dynamic response calculations.

The following list summarizes the NX Nastran rotor dynamics capabilities inversion 6.1.

NX Nastran Rotor Dynamics Capabilities

• Complex modal solution (SOL 110) is supported.

• Frequency response solution (SOL 111) is supported.

• Transient response solution (SOL 112) is supported.

• The complex eigenvalues for each rotor speed is calculated, along with thedamping and the whirl direction.

• Complex results in Excel format can be stored for Campbell diagram plots.

• Synchronous and asynchronous excitations can be defined.

Rotor Dynamics 45

• Symmetric and unsymmetric rotors are supported.

• Multiple rotors are supported.

• Each rotor can be evaluated either at the same or different speed.

• Both inline and non-inline models are supported.

• Both stationary and rotating reference frames are supported.

• Differential stiffness is included to compute centrifugal softening effects.

• Geometric stiffening and centrifugal softening are included.

• Dynamic load scenarios such as mass and force imbalance and any standardNastran dynamic loads can be included.

• Both internal damping acting on the rotating portion and/or external dampingacting on the fixed portion and bearings are supported.

46 Rotor Dynamics

Rotor Dynamics Overview

The free vibrations of a flexible rotor are computed from the following complexeigenvalue analysis problem:

Here m, b, k are the modal mass, damping and stiffness matrices. The c and hmatrix components of the equilibrium equation are proportional to a sequence ofrotation speeds (denoted by capital omega), and included in the input file. The c isthe modal gyroscopic matrix, and contains moments due to nodal rotations, andthe h is the circulatory (internal structural damping) matrix.

The rotating effects are included with the conventional finite element model of thestructure. The above modal complex eigenvalue problem is solved in a loop overthe rotor speeds. The resulting eigenvectors are the whirl mode shapes and theeigenvalues are the whirl modes.

The eigenvalues of this quadratic eigenvalue problem appear in complex conjugatepairs: l=wz(+2j) with natural frequency f, where w=2πf and the viscous dampingcoefficient is z. The natural frequencies are dependent on the rotor speed. Only thesolutions with positive natural frequencies are considered.

The Campbell diagram, shown below, is a method of presenting and interpretingthe rotor dynamics results. In the diagram, the natural frequencies (verticalaxis) are plotted as the function of the rotor speed (horizontal axis). The line 1Prepresenting equal frequency and rotor speed is also plotted. Critical speed valuesare where the latter line intersects any of the natural frequency curves.

Rotor Dynamics 47

For the Campbell diagram example shown, the horizontal mode 1 represents alinear motion, and modes 2 and 3 show the forward (direct) whirl and backward(reverse) whirl modes, respectively, which diverge as the spin speed increases.When the backward whirl frequency or the forward whirl frequency equal the spinspeed Ω, indicated by the intersections A and B with the 1P line, the response ofthe rotor may show a peak. This is called a critical speed.

For un-symmetric rotors, there are two critical speeds in the diagram. Betweenthese values the rotor is unstable. For symmetric rotors there is one criticalspeed at which the rotor is unstable. Based on this, a stability diagram with realeigenvalues or damping as function of rotor speed may be established.

The governing equation of frequency response in modal space with rotor dynamicsterms, in a fixed coordinate system, and considering the load to be independentof the speed of the rotation is:

The lower case omega is the circular frequency and this is called an asynchronoussolution. The load in this case could still have frequency dependence, as shown bythe m discrete excitation frequencies defined above.

48 Rotor Dynamics

In the case the load is dependent on the speed of rotation (called synchronousanalysis) the governing equation, still in a fixed reference system, is as follows:

Here n denotes the number of synchronous rotation speeds at which the analysis isexecuted.

The synchronous analysis case is applicable to various centrifugal loads based onmass or force imbalances of the rotor. The asynchronous analysis is applicable tocases like gravity loads.

The rotating system analysis can also be done in a rotating reference system, andyou must specify the system that is more advantageous to a particular problem.In a rotating reference system the rotor dynamic analysis involves additionalterms, like the geometric or differential stiffness matrix due to centrifugal stress,and a centrifugal softening matrix. The gyroscopic matrix also contains Coriolisterms in the rotational reference system.

Rotor Dynamics 49

Rotor Dynamics Examples

Example 1: Two Identical Uncoupled Rotors with Different Speeds

This model consists of two identical uncoupled rotors rotating at different speedsas shown in Figure2-1 . Both rotors are attached to “ground” by SPC.

Figure 2-1. Two identical uncoupled rotors

The Campbell diagram results of the SOL 110 analysis are shown in Figure 2-2.The abscissa is the rotor speed defined on the ROTORD card but the second rotoris rotating two times faster.

50 Rotor Dynamics

Figure 2-2. Campbell diagram for two identical uncoupled rotors withdifferent speeds

Listing 2-1 shows the input file.

NASTRAN $$$ two equal rotors with different speeds$assign output4=’sub110-267a.gpf’,unit=22, form=formatted$SOL 110$time 20000

Rotor Dynamics 51

diag 8$CEND$ECHO = NONESPC = 1$SET 1 = 1011,2011$DISP = 1RMETHOD = 99$METHOD = 1CMETHOD = 2$BEGIN BULK$PARAM ROTGPF 22PARAM POST -1PARAM OGEOM NOPARAM AUTOSPC YESPARAM GRDPNT 0$$ sid rstart rstep numstep refsys cmout runit funitROTORD 99 0.0 5. 100 FIX -1.0 HZ HZ +ROT0$ zstein orbeps rotprt sync etype eorder+ROT0 NO 1.0E-3 3 1 1 1.0 +ROT1$ rid1 rset1 rspeed1 rcord1 w3-1 w4-1 rforce1+ROT1 1 11 1.00 1 400.0 400.0 +ROT2$ rid1 rset1 rspeed1 rcord1 w3-1 w4-1 rforce1+ROT2 2 12 2.00 2001 400.0 400.0$ROTORG 11 1001 THRU 1021ROTORG 12 2001 THRU 2021$EIGRL 1 8 1EIGC 2 CLAN 16EIGC 3 HESS 16$include ’mod-067a.dat’include ’mod-067z.dat’$ENDDATA

Listing 2-1. Input File for Two Uncoupled Rotors with Different Speeds

Listing 2-2 shows the bulk data deck for the second rotor.

cord2r 2001 0. 0. 0. 0. 0. 1. +xcr2001+xcr2001 1. 0. 0.$$ . . . . . . . . .pbar 2000 2000 2.396+6 2.009+6 2.009+61.840+10 +p01ugaa+p01ugaa 0. 32.9 32.9 0. 0. -32.9 -32.9 0. +p01ugab+p01ugab 0.9 0.9$mat1 2000 2.000+5 0.3 2.000-2$$ stiff bar for rotor section

52 Rotor Dynamics

pbar 2009 2009 10000. 1.000+8 1.000+8 2.000+9$mat1 2009 2.000+9 0.3 2.000-2$$ Nodes$grid 2001 0. 0. 1000.grid 2002 0. 0. 1050.grid 2003 0. 0. 1100.grid 2004 0. 0. 1150.grid 2005 0. 0. 1200.grid 2006 0. 0. 1281.78grid 2007 0. 0. 1300.grid 2008 0. 0. 1350.grid 2009 0. 0. 1400.grid 2010 0. 0. 1450.grid 2011 0. 0. 1500.grid 2012 0. 0. 1550.grid 2013 0. 0. 1600.grid 2014 0. 0. 1650.grid 2015 0. 0. 1700.grid 2016 0. 0. 1718.22grid 2017 0. 0. 1800.grid 2018 0. 0. 1850.grid 2019 0. 0. 1900.grid 2020 0. 0. 1950.grid 2021 0. 0. 2000.$$ Elements$cbar 2001 2000 2001 2002 1. 0. 0.cbar 2002 2000 2002 2003 1. 0. 0.cbar 2003 2000 2003 2004 1. 0. 0.cbar 2004 2000 2004 2005 1. 0. 0.cbar 2005 2000 2005 2006 1. 0. 0.cbar 2006 2009 2006 2007 1. 0. 0.cbar 2007 2009 2007 2008 1. 0. 0.cbar 2008 2009 2008 2009 1. 0. 0.cbar 2009 2009 2009 2010 1. 0. 0.cbar 2010 2009 2010 2011 1. 0. 0.cbar 2011 2009 2011 2012 1. 0. 0.cbar 2012 2009 2012 2013 1. 0. 0.cbar 2013 2009 2013 2014 1. 0. 0.cbar 2014 2009 2014 2015 1. 0. 0.cbar 2015 2009 2015 2016 1. 0. 0.cbar 2016 2000 2016 2017 1. 0. 0.cbar 2017 2000 2017 2018 1. 0. 0.cbar 2018 2000 2018 2019 1. 0. 0.cbar 2019 2000 2019 2020 1. 0. 0.cbar 2020 2000 2020 2021 1. 0. 0.$$ Rotor mass and inertiaconm2 2111 2011 0.5 +con2111+con2111 13889. 13889. 11905.$$ Connectionn to bearingsrbe2 1201 2001 123456 1201rbe2 1221 2021 123456 1221$grid 1101 0. 0. 1000.grid 1121 0. 0. 2000.

Rotor Dynamics 53

$grid 1201 0. 0. 1000.grid 1221 0. 0. 2000.$celas1 1101 1101 1101 1 1201 1celas1 1102 1102 1101 2 1201 2$celas1 1121 1121 1121 1 1221 1celas1 1122 1122 1121 2 1221 2$ . . .pelas 1101 49342.pelas 1102 49342.pelas 1121 49342.pelas 1122 49342.$cdamp1 1301 1301 1101 1 1201 1cdamp1 1302 1302 1101 2 1201 2$cdamp1 1321 1321 1121 1 1221 1cdamp1 1322 1322 1121 2 1221 2$pdamp 1301 15.pdamp 1302 15.pdamp 1321 15.pdamp 1322 15.$spc 1 2001 36spc1 1 123456 1101 1121$$ Point for force applicationgrid 2899 10. 0. 1600.$rbe2 3500 2899 123456 2013

Listing 2-2. Bulk Data Deck for the second rotor

The results summary is shown in Listing2-3. Here the asynchronous crossings areonly with the 1P line. The instability of the faster rotor occurs at the half value ofthe reference rotor speed. Here a loop over the excitation line for each rotor wasmade. There are 16 solutions, including multiple solutions.

WHIRL RESONANCE SOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

1 5.10594E+01 FORWARD2 5.10594E+01 BACKWARD3 5.10617E+01 FORWARD4 5.10617E+01 BACKWARD5 1.12035E+02 BACKWARD6 4.04315E+02 FORWARD7 9.27005E+01 BACKWARD

INSTABILITIES SOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

START 1 3.90129E+02 FORWARDSTART 3 1.95085E+02 FORWARD

54 Rotor Dynamics

CRITICAL SPEEDS FROM SYNCRONOUS ANALYSISSOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

1 5.10809E+01 BACKWARD2 5.10809E+01 FORWARD3 5.10822E+01 LINEAR4 5.10822E+01 LINEAR5 9.30164E+01 BACKWARD6 1.12449E+02 BACKWARD8 4.05455E+02 FORWARD9 2.55405E+01 BACKWARD10 2.55405E+01 FORWARD11 2.55411E+01 LINEAR12 2.55411E+01 LINEAR13 5.62257E+01 BACKWARD14 6.41057E+01 BACKWARD15 1.01361E+02 FORWARD16 2.02733E+02 FORWARD

Listing 2-3. Results summary for two identical uncoupled rotors withdifferent speeds

Rotor Dynamics 55

Example 2: Two Different Uncoupled Rotors with Different Speeds

The mass and inertia of the fast rotor in Example 1 is reduced by a factor of two.Hence the eigenfrequencies are increased by the square root of two.

Eigenvalue Analysis with SOL 110

The Campbell diagram is shown in Figure 2-3.

Figure 2-3. Campbell diagram for two different uncoupled rotors withdifferent speeds

56 Rotor Dynamics

Listing 2-4 shows the results summary.

WHIRL RESONANCE SOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

1 5.10594E+01 FORWARD2 5.10594E+01 BACKWARD3 7.21833E+01 BACKWARD4 7.21833E+01 FORWARD5 1.12035E+02 BACKWARD6 4.04315E+02 FORWARD7 1.30632E+02 BACKWARD

INSTABILITIES SOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

START 1 3.90129E+02 FORWARDSTART 4 2.75891E+02 FORWARD

CRITICAL SPEEDS FROM SYNCRONOUS ANALYSISSOLUTION ROTOR SPEED WHIRLNUMBER HZ DIRECTION

1 5.10809E+01 BACKWARD2 5.10809E+01 FORWARD3 7.22410E+01 LINEAR4 7.22411E+01 LINEAR5 1.12449E+02 BACKWARD6 1.31545E+02 BACKWARD8 4.05455E+02 FORWARD9 2.55405E+01 BACKWARD10 2.55405E+01 FORWARD11 3.61205E+01 LINEAR12 3.61205E+01 LINEAR13 6.41057E+01 BACKWARD14 7.95152E+01 BACKWARD15 1.01361E+02 FORWARD16 2.86707E+02 FORWARD

Listing 2-4. Results summary for two different uncoupled rotors atdifferent speeds

Frequency Response Analysis with SOL 111

The additional input for asynchronous frequency response analysis at the rotorspeed 100 Hz is shown in Listing 2-5, and the additional XYPUNCH cards in thecase control deck are shown in Listing 2-6. According to the Campbell diagram inFigure 2-3, the first rotor must have resonance peaks around 50 and 200 Hz. Thisis confirmed with the response curve in Figure 2-4. The peaks for the second rotorare expected around 70 and 315 Hz as shown in Figure 2-5.

Rotor Dynamics 57

$ SID RSTART RSTEP NUMSTEP REFSYS CMOUT RUNIT FUNITROTORD 99 100.0 5. 1 FIX -1.0 HZ HZ +ROT0$ ZSTEIN ORBEPS ROTPRT SYNC ETYPE EORDER+ROT0 NO 1.0E-6 3 0 1 1.0 +ROT1$ RID1 RSET1 RSPEED1 RCORD1 W3-1 W4-1 RFORCE1+ROT1 1 11 1.0 1 400.0 400.0 +ROT2$ second rotor$ rid1 rset1 rspeed1 rcord1 w3-1 w4-1 rforce1+ROT2 2 12 2.0 1 400.0 400.0$ROTORG 11 1001 THRU 1899$ second rotorROTORG 12 2001 THRU 2899$$$ additional excitation for the second rotor$ sid grid dofDAREA 131 2899 1 1.0DAREA 132 2899 2 1.0$DPHASE 141 2899 1 0.0$ forwardsDPHASE 142 2899 2 90.0$ backwards$DPHASE 142 2899 2 -90.0

Listing 2-5. Modified ROTORD card and additional excitation input forthe second rotor

XYPUNCH ACCE RESP 1 /2899(T1RM),2899(T2RM)XYPUNCH ACCE RESP 1 /2899(T1IP),2899(T2IP)XYPUNCH ACCE RESP 1 /2899(R1RM),2899(R2RM)

XYPUNCH ACCE RESP 1 /2899(R1IP),2899(R2IP)

Listing 2-6. Additional XPUNCH commands for the second rotor

58 Rotor Dynamics

Figure 2-4. Asynchronous Solution — Translation acceleration for thefirst rotor

Rotor Dynamics 59

Figure 2-5. Asynchronous Solution — Translation acceleration for thesecond rotor

A synchronous analysis with two rotors at different speed can be done. However,only one rotor can be synchronous at the same time. Looking at the Campbelldiagram in Figure 2-3, the crossing points of the 1P line with the first rotor showresonances with the forward whirl of the first rotor around 50 and 410 RPM. Thisresponse plot is shown in Figure 2-6.

60 Rotor Dynamics

Figure 2-6. Synchronous solution — Displacement response of rotor 1

Rotor Dynamics 61

Example 3: Two Different Rotors with Different Speeds, Coupled via aHousing

In the more general case, the two rotors are connected to a flexible non-rotatingstructure. The structure is shown in Figure 2-7. Now the rotors are connected toa beam structure via CELAS (10 times stiffer than in the previous cases). Thebeam structure is constrained in the mid point between the rotors. The rotors areconstrained in z-direction and in rotation about the z-axis. The real modes areshown in Figure 2-8. The four first modes are mainly translation but the rotorsare now coupled and there is also some tilt in the modes. The four last modesare mainly tilt modes.

Figure 2-7. General case of two different rotors with different speedsmounted on a housing

62 Rotor Dynamics

Mode 1

Mode 2

Rotor Dynamics 63

Mode 3

Mode 4

64 Rotor Dynamics

Mode 5

Mode 6

Rotor Dynamics 65

Mode 7

66 Rotor Dynamics

Mode 8

Figure 2-8. Rotor results — real modes

The Campbell diagram is shown in Figure 2-9. The results of a forward whirlasynchronous response analysis with SOL 111 are shown in Figure 2-10 for a pointon rotor 1 (with the large mass) and in Figure 2-11 for a point on rotor 2. Due tothe coupling of the modes, the translation peaks for both rotors can be seen inboth plots. There is also a weak coupling of the higher tilt modes but the secondpeak can hardly be seen in the plots.

Rotor Dynamics 67

Figure 2-9. Campbell diagram. Curves with symbols were calculated withSOL 110

68 Rotor Dynamics

Figure 2-10. Asynchronous forward whirl response analysis, point onrotor 1

Rotor Dynamics 69

Figure 2-11. Asynchronous forward whirl response analysis, point onrotor 2

70 Rotor Dynamics

Example 4: Transient Analysis

In the modal transient analysis, the following equation is solved in the fixedreference system:

In the rotating reference system, the following equation is solved:

The equations are solved numerically with the standard NX NASTRAN numericalmethods. The initial conditions are equal to zero:

For the transient analysis, you must provide an excitation function which iscompatible with the time step (TSTEP) used and with the rotor speed values on theROTORD card in NX Nastran. For synchronous and asynchronous analysis, a timefunction with linearly varying frequency must be defined as shown in Figure 2-12.

Rotor Dynamics 71

Figure 2-12. Frequency as a function of time

For a linearly varying frequency we have

The slope of the curve is a. The angle is

The instantaneous frequency is the time derivative of the angle

72 Rotor Dynamics

In order to obtain a frequency F at time T we have

The slope of the curve is then given by

For example to simulate 0 to 500 Hz in 10 seconds, the constant is

At the end of the simulation, the frequency is

and the period is

The time step is now dependent on the wanted number of integration points percycle. A reasonable value is 10 points and, therefore, a time step of 0.0002 secondscan be used. This means 50,000 time steps for the simulation of 10 seconds. Theexcitation frequency as function of time is shown in Figure 2-12.

Similar to the frequency domain where a rotating force was defined by real andimaginary parts (or 90 degrees phase shift) in x- and y-direction, a rotating forcecan be defined in the time domain by taking sine and cosine functions for the x-and y- axis respectively. Sine and cosine functions are shown for the first second ofsimulation in Figure 2-13. The last 0.01 second of simulation is shown in Figure2-14. Here, the integration points are shown by symbols.

Rotor Dynamics 73

Figure 2-13. Time functions during the first second of simulation

74 Rotor Dynamics

Figure 2-14. Time functions during the last 0.01 second of simulation. Thefrequency is 500 Hz.

The data must be entered into NX Nastran by means of TABLED1 cards. For theexample shown, Excel can be used to calculate the time function and write thedata out in NX Nastran format.

Transient Response — Asynchronous Analysis

The asynchronous analysis is done for a fixed rotor speed and with a linearlyvarying excitation function. The rotor dynamic input file is shown in Listing 2-7.Part of the time function, which has 50,000 values, is shown in Listing 2-8. Thecurve with ID 121 is the sine function and the curve 122 is the cosine function. Theexcitation is a forward whirl motion with sine component in x-direction and cosinecomponent in y-direction. The frequency is linearly varying from 0 to 500 Hz. Onthe ROTORD card, a rotor speed of 300 Hz is defined and the SYNC flag is set tozero. The ETYPE is 1, which means that the excitation force is defined as mass

Rotor Dynamics 75

unbalance that is multiplied by in order to obtain a force. The EORDER is setto 1.0. The model is a rotating cylinder and is the same as used in the previousexample.

$ SID RSTART RSTEP NUMSTEP REFSYS CMOUT RUNIT FUNITROTORD 99 300.0 5. 1 FIX -1.0 HZ HZ +ROT0$ ZSTEIN ORBEPS ROTPRT SYNC ETYPE EORDER+ROT0 NO 1.0E-6 3 0 1 1.0 +ROT1$ RID1 RSET1 RSPEED1 RCORD1 W3-1 W4-1 RFORCE1+ROT1 1 11 1.0 1 400.0 400.0$ROTORG 11 1001 THRU 1899$$ sid s s1 rload rloadDLOAD 100 1.0-3 1.0 101 1.0 102$$ darea delay type tabledTLOAD1 101 131 0 121TLOAD1 102 132 0 122$$ sid grid dofDAREA 131 1899 1 1.0DAREA 132 1899 2 1.0$TSTEP 201 50000 0.0002$include ’sincos-500.dat’$include ’mod-067a.dat’$

Listing 2-7. Input data for asynchronous rotor dynamic analysis for afixed rotor speed of 300 Hz using 50,000 time steps of 0.0002 seconds.

$ 0 to 500 Hz in 10 seconds$ sinustabled1 121 +tbl1000+tbl1000 0. 0. 2.000-4 6.283-6 4.000-4 2.513-5 6.000-4 5.655-5+tbl1001+tbl1001 8.000-4 1.005-4 1.000-3 1.571-4 1.200-3 2.262-4 1.400-3 3.079-4+tbl1002

$ etc+tb13500endt$ cosinustabled1 122 +tbl5000+tbl5000 0. 1. 2.000-4 1. 4.000-4 1. 6.000-4 1. +tbl5001$ etc.+tb17499 9.9992 -0.80947 9.9994 -0.31012 9.9996 0.30754 9.9998 0.80845+tb17500+tb17500endt

Listing 2-8. Part of the include file with the excitation functions

The result of the analysis is shown in Figure 2-15 for the displacement when theexcitation is increased from 0 to 500 Hz in 10 seconds. There is a clear resonancepeak at 1 second which is equivalent to 50 Hz. This is the forward whirl resonance

76 Rotor Dynamics

of the translation. Figure 2-16 shows the same item but now the excitation isincreased from 0 to 500 Hz in one second. The maximum amplitudes now occurafter 0.1 second and the rotor is not really in resonance because the structurehas not enough time to respond and the resonance point is passed quickly. Themaximum amplitude in the slowly increasing case is 1.5 mm and in the fast caseonly 0.5 mm.

Figure 2-15. Displacement response of the translation when the excitationfrequency is increasing from 0 to 500 Hz in 10 seconds and passing

through the critical speed

Rotor Dynamics 77

Figure 2-16. Displacement response of the translation when the excitationis accelerating from 0 to 500 Hz in 1 second and passing through the

critical speed

Transient Response — Synchronous Analysis

The number of time steps on the TSTEP card must be equal to NUMSTEP on theROTORD card. The rotor speed must be defined as the range up to 500 Hz. It isnot possible to start at zero rotor speed because then the excitation force will bezero and the program will stop. The SYNC flag must be set to one. The input isshown in Listing 2-9.

$$ SID RSTART RSTEP NUMSTEP REFSYS CMOUT RUNIT FUNITROTORD 99 0.01 0.01 50000 FIX -1.0 HZ HZ +ROT0$ ZSTEIN ORBEPS ROTPRT SYNC ETYPE EORDER+ROT0 NO 1.0E-6 3 1 1 1.0 +ROT1

78 Rotor Dynamics

$ RID1 RSET1 RSPEED1 RCORD1 W3-1 W4-1 RFORCE1+ROT1 1 11 1.0 1 400.0 400.0$TSTEP 201 50000 0.0002$

Listing 2-9. Input for synchronous analysis

The results of a synchronous analysis are shown in Figure 2-17. The excitationis now along the 1P line in the Campbell diagram. The rotor speed is equal(synchronous) to the excitation frequency and the simulation shows how the rotorbehaves when the critical speed is passed.

Rotor Dynamics 79

80 Rotor Dynamics

Figure 2-17. Running through the translation peak at around 50 Hz

ROTORD 81Defines rotor dynamics solution options (SOLs 110, 111, and 112).

Updated ROTORD Bulk Entry

ROTORD Defines rotor dynamics solution options (SOLs 110, 111, and 112).

Defines rotor dynamics solution options for SOLs 110, 111, and 112.

Format:

1 2 3 4 5 6 7 8 9 10ROTORD SID RSTART RSTEP NUMSTEP REFSYS CMOUT RUNIT FUNIT ++ ZSTEIN ORBEPS ROTPRT SYNC ETYPE EORDER+ RID1 RSET1 RSPEED1 RCORD1 W3_1 W4_1 RFORCE1+ RID2 RSET2 RSPEED2 RCORD2 W3_2 W4_2 RFORCE2....

+ RID10 RSET10 RSPEED10 RCORD10 W3_10 W4_10 RFORCE10

Example:ROTORD 998 0.0 5000.0 58 fix -1.0 cps +r0

+r0 no +r1

+r1 1 11 1 0.0 0.0 1 +r2

+r2 2 12 1 0.0 0.0 +r3

+r3 3 13 1 0.0 0.0 +r4

+r4 4 14 1 0.0 0.0 +r5

+r5 5 15 2 1 0.0 0.0 +r6

+r6 6 16 1 0.0 0.0 +r7

+r7 7 17 1 0.0 0.0 +r8

+r8 8 18 1 0.0 0.0 +r9

+r9 9 19 1 0.0 0.0 +r10

+r10 10 20 1 0.0 0.0 10

Fields:

Field Contents

SID Set identifier for all rotors. Must be selected in the case controldeck by RMETHOD=SID.

RSTART Starting value of rotor speed. (Real ≥ 0.0)

RSTEP Step-size of rotor speed. (Real > 0.0)

82 ROTORDDefines rotor dynamics solution options (SOLs 110, 111, and 112).

Field Contents

NUMSTEP Number of steps for rotor speed including RSTART. (Integer > 0)

REFSYS Reference system. (default=‘ROT’)

= ‘FIX’ analysis is performed in the fixed reference system.

= ‘ROT’ analysis is performed in the rotational reference system.

CMOUT Rotor speed for complex mode output request. (Integer ≥ 0)

= -1.0 output complex modes and whirl direction for all RPM.

= 0.0 no complex modes and no whirl direction are output. (default)

> 0.0 rotor speed value for which complex modes will be calculatedand written to F06 or OP2.

RUNIT Units used for rotor speed input (RSTART and RSTEP) and output(units for output list and Campbell’s diagram output).

= ‘RPM’ revolutions per minute. (default)

= ‘CPS’ cycles per second.

= ‘HZ’ cycles per second.

= ‘RAD’ radians per second.

FUNIT Units used for frequency output (Campbell’s diagram output).

= ‘RPM’ revolutions per minute. (default)

= ‘CPS’ cycles per second.

= ‘HZ’ cycles per second.

= ‘RAD’ radians per second.

ZSTEIN Option to incorporate Steiner’s inertia terms. (default=NO)

ORBEPS Threshold value for detection of whirl direction. (default=1E-6)

ROTORD 83Defines rotor dynamics solution options (SOLs 110, 111, and 112).

Field Contents

ROTPRT Controls .f06 output options.

= 0 no print. (default)

= 1 print generalized matrices.

= 2 print eigenvalue summary and eigenvectors at each RPM.

= 3 combination of 1 & 2.

SYNC Specifies if a rotor dynamics response calculation (SOL 111) issynchronous or asynchronous. (Integer)

=1 synchronous (default)

=0 asynchronous

ETYPE Excitation type.

=1 Mass unbalanced (default). Specify mass unbalance = m x r onDLOAD bulk entry and the program will multiply by Ω2.

=0 Force excitation. Specify force = m x r x Ω2 on DLOAD bulkentry.

EORDER Excitation order

= 1.0 (default)

= 0.0 Forward whirl (modes crossing with 0P line)

= 2.0 Backward whirl (modes crossing with 2P line)

This value is always 1.0 for fixed reference system.

RIDi Rotor ID for output identification (default=i); must be unique withrespect to all other RIDi values.

RSETi Refers to a RSETID value on a ROTORG bulk entry. EachROTORG bulk entry specifies the grids for a single rotor. (Integer)

RSPEEDi Scales the speed defined by RSTART, RSTEP, and NUMSTEP(default = 1.0).

RCORDi Points to CORD** entry specifying rotation axis or rotor i as z.(default=0 for global z axis)

84 ROTORDDefines rotor dynamics solution options (SOLs 110, 111, and 112).

Field Contents

W3_i Reference frequency for structural damping defined by PARAM Gfor rotor i. (default=0.0)

W4_i Reference frequency for structural damping defined on materialcard for rotor i. (default=0.0)

RFORCEi Points to RFORCE bulk data entry for rotor i. (Default=0 forno rotational force applied; a rotational force is required fordifferential stiffness to be calculated.)

Remarks:

1. Any entries where defaults exist are optional. Thus, if the defaults are acceptablefor a particular model, then a continuation card would not be needed.

2. There is a maximum limit of 10 rotors (i.e. 11 continuation cards).

3. The Steiner’s term option (ZSTEIN) should only be used for analyzing the “stiff”part of the rotor. In the rotating system analysis, there is a stiffening effect ofthe centrifugal forces. The gyroscopic matrix is calculated in the fixed system.

4. The W3 parameter defines the reference frequency for the structural dampingdefined by PARAM G.

5. The W4 parameter defines the reference frequency for the structural dampingdefined on the material cards.

6. The static centrifugal force is calculated for unit speed measured in rad/sec. Onthe RFORCE card, the unit of Hz is used, thus the conversion 1/2(π)=0.159155must be used.

7. For calculating the modal frequency response using synchronous analysis, therotation speeds are defined by the RSTART, RSTEP and NUMSTEP fields on theROTORD bulk entry. The frequencies corresponding to these rotation speeds arecomputed and the dynamic loads are calculated accordingly.

8. For calculating the modal frequency response using asynchronous analysis,the unique rotation speed is defined by the RSTART field on the ROTORDbulk entry. The RSTEP and NUMSTEP fields in this case will be ignored. Thefrequency and dynamic load definitions are taken from the standard FREQ,DLOAD, and RLOAD bulk entries.

Grid Point Force Enhancement 85Grid Point Force Output Request

2.3 Grid Point Force EnhancementGrid point force output can now be requested in frequency-based analyses, as wellas SORT2. The GPFORCE case control entry is now available for the solutiontypes 101, 103, 105, 106, 108, 109, 111, 112, 114, 115, 116, 118, 144, 146, 187, and200 (analysis=MTRAN, MFREQ, and DFREQ).

Updated GPFORCE Case Control Command

GPFORCE Grid Point Force Output Request

Requests grid point force balance at selected grid points.

Format:

Examples:

GPFORCE=ALLGPFORCE=17GPFORCE(SORT2,PRINT,PUNCH,PHASE) = 123

Describers:

Describer Meaning

SORT1 Output will be presented as a tabular listing of grid points foreach load, frequency, eigenvalue, or time depending on solutionsequence. (Default)

SORT2 Output will be presented as a tabular listing of load, frequency,eigenvalue, or time for each grid point.

PRINT The printer will be the output medium. (Default)

PUNCH The punch file will be the output medium.

NOPRINT Generates, but does not print, grid point force balance results.

REAL orIMAG

Requests rectangular format (real and imaginary) of complexoutput. Use of REAL or IMAG yields the same output. (Default)

86 GPFORCEGrid Point Force Output Request

Describer Meaning

PHASE Requests polar format (magnitude and phase) of complex output.Phase output is in degrees.

ALL Grid point force balance for all grid points will be output.

n Set identification number of a previously appearing SETcommand. Only grid points with identification numbers thatappear on this SET command will be included in the grid pointforce balance output. (Integer>0)

Remarks:

1. Both PRINT and PUNCH may be requested.

2. The printing of the grid point forces will be suppressed if PARAM,NOGPF,-1appears in the Bulk Data.

3. The Bulk Data entry PARAM,NOELOF,+1 will cause the output of the grid pointforces to be aligned with the edges of the two-dimensional elements. The defaultvalue of -1 will suppress this output.

4. The Bulk Data entry PARAM,NOELOP,+1 will cause the output of the sum ofthe forces parallel to the edges of adjacent elements. The default value of -1 willsuppress this output.

5. The output of grid point forces aligned with the edges of elements is available forthe following elements:

CBARCRODCBEAMCSHEARCONRODCTRIA3

The positive direction for grid point forces aligned with the edges of elements isfrom the reference point to the load point as indicated on the printed output.

6. Grid point force balance is computed from linear and nonlinear elements,the sum of applied and thermal loads, and MPC and SPC forces. Effects notaccounted for include those from mass elements in dynamic analysis (inertialoads), general elements, DMIG entries, and boundary loads from upstreamsuperelements. These effects may lead to an apparent lack of equilibrium atthe grid point level. The following table summarizes those effects that areconsidered and those effects that are ignored in the calculation of grid pointforces in the global coordinate system:

GPFORCE 87Grid Point Force Output Request

Contributions Included Contributions Ignored

Applied Loads GENEL Forces

SPC Forces DMIG and DMI Forces

Element Elastic Forces Boundary Loads from UpstreamSuperelements

Thermal Loads

MPC and Element Forces

7. Only the element elastic forces are included when the grid point forces arealigned with the edges of elements.

8. In inertia relief analysis, the GPFORCE output related to SPCFORCES andapplied loads is interpreted differently for SOLs 101 and 200:

• In SOLs 101 and 200, the SPCFORCE and applied load output includes boththe effect of inertial loads and applied loads.

9. When pressure loads are applied, the GPFDR module uses the discrete loadvector and does not include any distributed effects.

10. Grid point force output is available for nonlinear static analysis (SOLs 106).All other nonlinear solution sequences do not support grid point force output.PARAM,NOELOF and PARAM,NOELOP are not supported in nonlinear staticanalysis; therefore, Remarks 3,4,5 and 7 do not apply to SOL 106.

88 Additional Dynamics Enhancements

2.4 Additional Dynamics EnhancementsRMAXMIN Output Enhancements

The RMAXMIN case control command is used with a modal transient solution(SOL 112) to evaluate the maximum or minimum force, stress, and displacementcomponents at each output grid or element over an entire time history. In additionto the maximum/minimum output, an RMS for each component of force, stress, anddisplacement is also calculated and output.

In NX Nastran 6.1, the RMAXMIN case control command has been enhanced asfollows:

• RMAXMIN is now supported in a direct transient solution (SOL 109).

• New START and END inputs on RMAXMIN limit the evaluation over aspecific range in the time history.

• The new NPAVG input on RMAXMIN equals the number of peaks in the timehistory to be averaged for output. NPAVG=1, the default setting, outputsthe single highest peak.

• The new input RMXTRN on RMAXMIN turns on/off the normal printing oftransient output data when RMAXMIN is used. The value defined on theRMAXMIN case control works the same as the parameter RMXTRN, andtakes precedence over that parameter. By default, RMXTRN=OFF, and onlyRMAXMIN data is output.

See the RMAXMIN Output Enhancements chapter for details.

Damping Enhancements

The PBUSH, PBUSHT, and PSHELL bulk entries have been improved with theaddition of new damping inputs.

The PBUSH bulk entry has supported a single structural damping value (GE1)which applies to all 6 degrees-of-freedom. Now, the PBUSH bulk entry will alsosupport a value in each degree-of-freedom (GE1, GE2, GE3, GE4, GE5, GE6).

Similarly, the PBUSHT bulk entry supports a single tabulated frequencydependent structural damping (TGEID1), which applies to all 6 degrees-of-freedom.Now the PBUSHT bulk entry will also support tabulated frequency dependentstructural damping for each degree-of-freedom (TGEID1, TGEID2, TGEID3,TGEID4, TGEID5, TGEID6).

The PSHELL bulk entry will now support the structural damping coefficient (GE)included on the materialsMID1 = membrane materialMID2 = bending material

Additional Dynamics Enhancements 89

MID3 = transverse shearMID4 = membrane-bending coupling.Previously, the structural damping coefficient included on the MID1 materialwas used for all MIDi.

See the Element Enhancements chapter for details.

Nonstructural Mass Enhancements

You can define a nonstructural mass (NSM) on the PSHELL, PCOMP, PBAR,PBARL, PBEAM, PBEAML, PBCOMP, PROD, CONROD, PBEND, PSHEAR,PTUBE, PCONEAX, and PRAC2D property entries. The nonstructural mass isadded to the element structural mass to calculate the total mass of the element.

When you need to modify the mass of a few or many elements, the NSM input onthe property entries can be limiting. New nonstructural mass bulk entries havebeen created in NX Nastran 6.1 which allows more flexibility.

The new NSM and NSM1 bulk entries allow you to add nonstructural mass byproperty and/or element ID. Both have the TYPE field which points to either aproperty type, PSHELL for example, or ELEMENT, which indicates element ID’swill be entered.

NSM has the form

Type, Mass Value, Id, Mass Value,ID...,

and NSM1 has the form

Type, Mass Value, ID, ID, ID, ...,

Since each NSM and NSM1 has a single "TYPE", multiple NSM and/or NSM1entries can be created, then combined with the new NSMADD bulk entry to adjustthe nonstructural mass across various property types and/or elements.

See the Element Enhancements chapter for details.

CDAMP and CVISC Force Output

The CDAMP1, CDAMP2, CDAMP3, CDAMP4, and CDAMP5 entries define scalardampers in a manner similar to the scalar spring definitions. The associatedPDAMP entry contains only a value for the scalar damper.

The CVISC entry is a rod type element used to represent a viscous damper. It hasboth extensional and torsional viscous damping properties.

Previously, the CDAMPi and CVISC entries supported complex element forceoutput. Now when requesting element force output with the FORCE case controlcommand, real element forces will also be stored for these element types. Themode displacement method (PARAM,DDRMM,-1) must be selected for elementforce output.

Chapter

3 External Superelement Enhancements

92 Introduction

3.1 IntroductionAn external superelement is a reduced boundary representation of a full componentmodel stored in an external file such as an .op2, .op4, bulk data, or database. Afteryou create several external superelements in specific “creation” solutions, you canthen combine them in a full NX Nastran system analysis.

In previous releases of NX Nastran, the external superelement procedure requiredthree steps:

1. External superelements were created. This was performed once for eachsuperelement.

2. Superelement assembly and system analysis was performed.

3. External superelement results recovery was performed for each superelement,with no results recovery method for the entire system model.

Although this procedure is still supported, a more efficient procedure wascreated in NX Nastran 6.0. Step 3 is now included in step 2 such that externalsuperelement results are recovered during the system analysis, and results foreach superelement can optionally be combined in the .f06 output and into a singledatablock for post-processing the assembly.

3.2 NX Nastran 6.1 EnhancementsThe superelement workflow introduced in version 6.0 includes these enhancements:

• Grid Point Force Results Recovery

When grid point forces (GPFORCE) are requested in the superelementcreation run, the output transformation matrices are stored so that theseresults can be recovered in the system run.

• Controlling Name of DMIG Matrices

You can now control the name of DMIG matrices using the new DMIGSFIXdescriber. When multiple superelements are used together in a system run,controlling the name of DMIG matrices prevents conflicts from occurring.The updated EXTSEOUT case control command is included at the end of thischapter.

• Plotel Result Recovery

A PLOTEL bulk data entry defines a one dimensional dummy elementwhich is used in post-processing to visualize results on grids unconnected tostructural elements. In this release you can include PLOTEL bulk data entries

Superelement Workflow 93

in the superelement creation run, and the output transformation matricesfor displacement, velocity, acceleration, SPC forces and MPC force outputare automatically created for any DOF associated to the grids included ona PLOTEL definition.

• Grid Reference Coordinate Improvement

The grid bulk entry output written to the assembly file and punch file nowuses the same reference coordinate system used in the superelement creationrun. Any associated coordinate system definitions are also written into theassembly file and punch file.

3.3 Superelement Workflow

Figure 3-1. Superelement Workflow

1. Component Solutions

• Use EXTSEOUT case control to write reduced model to DMIG, OP2, DB,or OP4.

EXTSEOUT(ASMBULK,EXTBULK,EXTID=101,MATOP4=30)

94 Superelement Workflow

• Output requests included in the creation solution are used to store theoutput transformation matrices (OTMs) for results recovery in theassembly solution.

• The ASMBULK field can be used to generate bulk data entries related tothe subsequent superelement assembly process and store them on theassembly punch file (.asm). This data is to be included in the residualstructure portion of the main bulk data for the subsequent assemblysolution.

• The EXTBULK field can be used to generate bulk data entries related tothe external superelement and store them on the standard punch file(.pch). This data should be included at the bottom of the bulk data forthe subsequent assembly solution.

2. Assembly Solution with Results Recovery

• Insert “BEGIN SUPER” entries for each previous run.

$_BEGIN SUPER = 101INCLUDE ’superelement101.pch’

• Any assembly files created in step 1 should be included with the residualstructure data.

INCLUDE ’superelement_01.asm’

• The parameter SECOMB can be used to request that superelement results(both internal and external) be combined with the rest of the systemmodel results into a single data block.

param,secomb,yes

Examples 95

3.4 ExamplesExample 1, using the default storage, MATDB (or MATRIXDB):

Step 1: Superelement creation Step 2: System run$SOL 103TIME 5DIAG 5,6,8,13,15CENDextseout(extbulk,asmbulk,extid=100)TITLE = SE CREATE EXAMPLE1disp=allstre=allstra=allforc=allSPC = 105method= 100

BEGIN BULKaset1, 123456, 104, 108eigrl, 100, , , 8spoint, 1001, thru, 1008qset1, 0, 1001, thru, 1008GRID,104,,4.0,0.0,0.0GRID,105,,5.0,0.0,0.0GRID,106,,6.0,0.0,0.0GRID,107,,7.0,0.0,0.0GRID,108,,8.0,0.0,0.0GRID,109,,9.0,0.0,0.0GRID,110,,10.0,0.0,0.0CBAR,105,101,104,105,0.0,1.0,0.0CBAR,106,101,105,106,0.0,1.0,0.0CBAR,107,101,106,107,0.0,1.0,0.0CBAR,108,101,107,108,0.0,1.0,0.0CBAR,109,101,108,109,0.0,1.0,0.0CBAR,110,101,109,110,0.0,1.0,0.0PBAR,101,101,1.0,.0833,.0833,.0833MAT1,101,3.E7,,.3,0.001FORCE,104,105,,10.0,0.0,0.0,-1.0SPC1,105,123456,110$ENDDATA

assign se100=see103hna.MASTER’dblocate datablk=(extdb) convert(seid=100),

logical=se100$SOL 103TIME 5DIAG 5,6,8,13,15CENDTITLE = SYSTEM RUN EXAMPLE1SPC = 5disp=allstre=allstra=allforc=allSUBCASE 1SUPER= 100

SUBCASE 2SUPER= 0METHOD= 200

BEGIN BULKeigrl, 200, , , 6include ’see103hna.asm’GRID,10,,0.0,0.0,0.0GRID,11,,1.0,0.0,0.0GRID,12,,2.0,0.0,0.0GRID,13,,3.0,0.0,0.0CBAR,11,1,10,11,0.0,1.0,0.0CBAR,12,1,11,12,0.0,1.0,0.0CBAR,13,1,12,13,0.0,1.0,0.0CBAR,14,1,13,104,0.0,1.0,0.0PBAR,1,1,1.0,.0833,.0833,.0833MAT1,1,3.0E7,,.3, 0.001SPC1,5,123456,10SPC1,6,123456,11SPC1,7,123456,12$include ’see103hna.pch’$ENDDATA

96 Examples

Example 2, using DMIGDB storage option:

Step 1: Superelement creation Step 2: System runSOL 103TIME 5DIAG 5,6,8,13,15CENDextseout(extid=100,extbulk,asmbulk,dmigdb)TITLE = SE CREATE EXAMPLE2disp=allstre=allstra=allforc=allSPC = 105method= 100


assign se100=see103hnd.MASTER’dblocate datablk=(extdb) convert(seid=100),

logical=se100SOL 103TIME 5DIAG 5,6,8,13,15CENDTITLE = SYSTEM RUN EXAMPLE2SPC = 5disp=allstre=allstra=allforc=allSUBCASE 1SUPER= 100


BEGIN BULKeigrl, 200, , , 7include ’see103hnd.asm’GRID,10,,0.0,0.0,0.0GRID,11,,1.0,0.0,0.0GRID,12,,2.0,0.0,0.0GRID,13,,3.0,0.0,0.0grid, 15, , 8.0, 0., 0.CBAR,11,1,10,11,0.0,1.0,0.0CBAR,12,1,11,12,0.0,1.0,0.0CBAR,13,1,12,13,0.0,1.0,0.0CBAR,14,1,13,104,0.0,1.0,0.0PBAR,1,1,1.0,.0833,.0833,.0833MAT1,1,3.0E7,,.3, 0.001SPC1,5,123456,10SPC1,6,123456,11SPC1,7,123456,12$include ’see103hnd.pch’$ENDDATA

Examples 97

Example 3, using DMIGOP2 storage option:

Step 1: Superelement creation Step 2: System runassign output2=see103hng.op2’,

delete, unit=30 $$SOL 103TIME 5DIAG 5,6,8,13,15CENDextseout(asmbulk,extid=100,dmigop2=30,extbulk)TITLE = SE CREATE EXAMPLE3disp=allstre=allstra=allforc=allSPC = 105method= 100


$ assign input2 for external SE$assign inputt2=’see103hng.op2’, unit= 30 $$SOL 103TIME 5DIAG 5,6,8,13,15CENDTITLE = SYSTEM RUN EXAMPLE3SPC = 5disp=allstre=allstra=allforc=allSUBCASE 1SUPER= 100


BEGIN BULKeigrl, 200, , , 6include ’see103hng.asm’GRID,10,,0.0,0.0,0.0GRID,11,,1.0,0.0,0.0GRID,12,,2.0,0.0,0.0GRID,13,,3.0,0.0,0.0CBAR,11,1,10,11,0.0,1.0,0.0CBAR,12,1,11,12,0.0,1.0,0.0CBAR,13,1,12,13,0.0,1.0,0.0CBAR,14,1,13,104,0.0,1.0,0.0PBAR,1,1,1.0,.0833,.0833,.0833MAT1,1,3.0E7,,.3, 0.001SPC1,5,123456,10SPC1,6,123456,11SPC1,7,123456,12$include ’see103hng.pch’$ENDDATA

98 Examples

Example 4, using DMIGPCH storage option:

Step 1: Superelement creation Step 2: System runSOL 103TIME 5DIAG 5,6,8,13,15CENDextseout(asmbulk,dmigpch,extid=100)TITLE = SE CREATE EXAMPLE4disp=allstre=allstra=allforc=allSPC = 105method= 100


SOL 103TIME 5DIAG 5,6,8,13,15CENDTITLE = SYSTEM RUN EXAMPLE4SPC = 5disp=allstre=allstra=allforc=allSUBCASE 1SUPER= 100k2gg= kaaxm2gg= maax


BEGIN BULKeigrl, 200, , , 6include ’see103hnj.asm’GRID,10,,0.0,0.0,0.0GRID,11,,1.0,0.0,0.0GRID,12,,2.0,0.0,0.0GRID,13,,3.0,0.0,0.0CBAR,11,1,10,11,0.0,1.0,0.0CBAR,12,1,11,12,0.0,1.0,0.0CBAR,13,1,12,13,0.0,1.0,0.0CBAR,14,1,13,104,0.0,1.0,0.0PBAR,1,1,1.0,.0833,.0833,.0833MAT1,1,3.0E7,,.3, 0.001SPC1,5,123456,10SPC1,6,123456,11SPC1,7,123456,12$include ’see103hnj.pch’$ENDDATA

Examples 99

Example 5, using MATOP4 (or MATRIXOP4) storage option with twosuperelements:

Step 1:Superelement 1 creationASSIGN OUTPUT4=’s35212n.op4’,unit=30,delete,formatSOL 109CENDTitle = SE1 CREATE Example5extseout(extbulk,extid=10,matop4=30)SUBCASE 1disp = allstress = allstrain = allforce = all

BEGIN BULKPARAM,USETPRT,0aset1,123456,101,thru,104CBEAM 1005 7 1001 1000 10000................ENDDATA

Superelement 2 creationASSIGN OUTPUT4=’s35212nar.op4’,unit=31,deleteSOL 109CENDTitle = SE2 CREATE Example5extseout(asmbulk,extid=5060,matrixop4=31)SUBCASE 2disp = allstress = allstrain = allforce = allmpcforce = all

BEGIN BULKPARAM,USETPRT,0aset1,123456,101,thru,104CBAR 5005 6 5001 5005 10000. 10000.............ENDDATA

100 Examples

Step 2: System run with two superelements.PROJECT=’MODES’ASSIGN INPUTT4=’s35212n.op4’,unit=30,formatASSIGN INPUTT4=’s35212nar.op4’,unit=31SOL 103CENDTitle = SYSTEM RUN Example5ECHO = sortMAXLINES = 999999999SUBCASE 1SUPER=10METHOD=11disp = allstress = allstrain = allforce = all

SUBCASE 2SUPER=5060METHOD=50disp = allstress = allstrain = allforce = allmpcforce = all

SUBCASE 3SUPER=0METHOD=1SUPORT1=99disp = allstress = allstrain = allforce = allmpcforce = all

BEGIN BULKSEBULK 10 EXTOP4 MANUAL 30SECONCT 10 0 NO

101 101 102 102 103 103 104 104include ’s35212nar.asm’SETREE,0,10,5060EIGRL,1,-1.0, 80.CBAR 2000 4 109 100 10000................$include ’s35212n.pch’$include ’s35212nar.pch’$EIGRL,11,-1.0,160.EIGRL,50,-1.0,160.ENDDATA

Updated EXTSEOUT Case Control Command 101External Superelement Creation Specification

3.5 Updated EXTSEOUT Case Control CommandEXTSEOUT External Superelement Creation Specification

Specify the various requirements for the creation of an external superelement.

Format:

Examples:

EXTSEOUTEXTSEOUT(ASMBULK,EXTID=100)EXTSEOUT(ASMBULK,EXTBULK,EXTID=200)EXTSEOUT(EXTBULK,EXTID=300)EXTSEOUT(DMIGDB)EXTSEOUT(ASMBULK,EXTID=400,DMIGOP2=21)EXTSEOUT(EXTID=500,DMIGPCH)EXTSEOUT(ASMBULK,EXTBULK,EXTID=500,DMIGSFIX=XSE500,DMIGPCH)EXTSEOUT(ASMBULK,EXTBULK,EXTID=500,DMIGSFIX=EXTID,DMIGPCH)EXTSEOUT(STIF,MASS,DAMP,EXTID=600,ASMBULK,EXTBULK,MATDB)

See Remarks 10, 11, and 12.

Describers:

Describer Meaning

STIFFNESS Store the boundary stiffness matrix. See Remarks 1 and 2.

MASS Store the boundary mass matrix. See Remark 1.

DAMPING Store the boundary viscous damping matrix. See Remarks 1and 2.

K4DAMP Store the boundary structural damping matrix. See Remarks 1and 2.

102 EXTSEOUTExternal Superelement Creation Specification

Describer Meaning

LOADS Store the boundary static loads matrix. See Remarks 1 and 2.

ASMBULK Generate bulk data entries related to the subsequentsuperelement assembly process and store them on theassembly punch file (.asm). This data is to be included in themain bulk data portion of the subsequent assembly solution.See Remarks 4 and 13.

EXTBULK Generate bulk data entries related to the externalsuperelement and store them on the standard punch file(.pch). This data is used in the BEGIN SUPER portion of thebulk data of the subsequent assembly solution. EXTBULK isignored if DMIGPCH or MATOP4 (see description below) isspecified. See Remarks 5 and 6.

EXTID = seid seid (integer>0) is the superelement ID to be used in theSEBULK and SECONCT bulk data entries stored on theassembly punch file (.asm) if ASMBULK is specified and in theBEGIN SUPER bulk data entry stored on the standard punchfile (.pch) if EXTBULK, DMIGPCH or MATOP4 is specified.See Remarks 3, 4, 5, and 7.

DMIGSFIX =cccccc

cccccc is the suffix (up to six characters and must not = anyEXTSEOUT keyword) that is to be employed in the names ofthe DMIG matrices stored on the standard punch file (.pch) ifthe DMIGPCH keyword is specified. See Remarks 8 – 11.

DMIGSFIX =EXTID

The seid defined by the EXTID keyword is the suffix that isto be employed in the names of the DMIG matrices stored onthe standard punch file (.pch) if the DMIGPCH keyword isspecified. See Remarks 8 – 11.

MATDB (orMATRIXDB)

Store the boundary matrices and other information on thedatabase (default).

DMIGDB Similar to MATDB (or MATRIXDB) except that the boundarymatrices are stored as DMIG bulk data entries on the database.

DMIGOP2=unit Store the boundary matrices as DMIG bulk data entries on anOUTPUT2 file whose Fortran unit number if given by unit(integer>0). See Remark 14.

EXTSEOUT 103External Superelement Creation Specification

Describer Meaning

DMIGPCH Store the boundary matrices as DMIG bulk data entries on thestandard punch file (.pch). See Remarks 6 – 13.

MATOP4= unit (orMATRIXOP4= unit)

Store the boundary matrices on an OP4 file whose Fortranunit number is given by unit (Integer>0). See Remarks 3, 5,6, 8, and 10.

Remarks:

1. If none of the describers STIFFNESS, MASS, DAMPING, K4DAMP, and LOADSare specified, then all matrices are stored.

2. STIFFNESS, DAMPING, K4DAMP, and LOADS may be abbreviated to STIF,DAMP, K4DA, and LOAD, respectively.

3. EXTID and an seid value must be specified if one or more of ASMBULK,EXTBULK, DMIGPCH, or MATOP4 are specified. If the DMIGSFIX=EXTIDform is employed along with the DMIGPCH keyword, the value seid may notexceed 999999, since this value becomes part of the names given to the DMIGmatrices generated on the standard punch file (.pch). See Remark 11.

4. If ASMBULK is specified, the following bulk data entries are generated andstored on the assembly punch file (.asm):

SEBULK seid …

SECONCT seid …

GRID entries for the boundary points

CORD2x entries associated with the above GRID entries

5. If DMIGPCH is not specified, but EXTBULK or MATOP4 is specified, thefollowing bulk data entries are generated and stored on the standard punchfile (.pch):

BEGIN SUPER seid


GRID entries for the interior points referenced by PLOTEL entries



EXTRN

ASET/ASET1

QSET/QSET1

SPOINT

PLOTEL

6. If DMIGPCH or MATOP4 is specified, then EXTBULK is ignored even if it isspecified.

7. If DMIGPCH is specified, the following bulk data entries are generated andstored on the standard punch file (.pch):

BEGIN SUPER seid



ASET/ASET1

SPOINT

DMIG entries for the requested boundary matrices

8. The DMIGSFIX keyword is ignored if DMIGPCH is not specified.

9. If DMIGPCH is specified without the DMIGSFIX keyword, then the boundaryDMIG matrices generated and stored on the standard punch file (.pch) will havenames of the following form:

KAAX (boundary stiffness matrix)

MAAX (boundary mass matrix)

BAAX (boundary viscous damping matrix)

K4AAX (boundary structural damping matrix)

PAX (boundary load matrix)

10. If the DMIGSFIX = cccccc form is employed along with the DMIGPCH keyword,then the boundary DMIG matrices generated and stored on the standard punchfile (.pch) will have names of the following form:

Kcccccc (boundary stiffness matrix)


Mcccccc (boundary mass matrix)

Bcccccc (boundary viscous damping matrix)

K4cccccc (boundary structural damping matrix)

Pcccccc (boundary load matrix)

11. If the DMIGSFIX = EXTID form is employed along with the DMIGPCHkeyword, then the boundary DMIG matrices generated and stored on thestandard punch file (.pch) will have names of the following form:

Kseid (boundary stiffness matrix)

Mseid (boundary mass matrix)

Bseid (boundary viscous damping matrix)

K4seid (boundary structural damping matrix)

Pseid (boundary load matrix)

12. If the DMIGPCH option is specified, the boundary DMIG matrices generated andstored on the standard punch file (.pch) may not be as accurate as the boundarymatrices resulting from other options (MATDB/MATRIXDB or DMIGOP2 orMATOP4/MATRIXOP4). Accordingly, this may result in decreased accuracy fromthe subsequent assembly job utilizing these DMIG matrices.

13. The punch output resulting from EXTSEOUT usage is determined byASMBULK, EXTBULK, DMIGPCH, and MATOP4 as follows:

• No ASMBULK, EXTBULK, DMIGPCH, or MATOP4 results in no punchoutput.

• ASMBULK, but no EXTBULK, DMIGPCH, or MATOP4 results in punchoutput being generated and stored on the assembly punch file (.asm). SeeRemark 4.

• No ASMBULK, but EXTBULK, DMIGPCH, or MATOP4, results in punchoutput being generated and stored on the standard punch file (.pch). SeeRemarks 5 or 6, as appropriate.

• ASMBULK and EXTBULK, DMIGPCH, or MATOP4, results in punchoutput consisting of two distinct and separate parts. One part is generatedand stored on the assembly punch file (.asm) as indicated in Remark 4.The other part is generated and stored on the standard punch file (.pch) asindicated in Remark 5 or 6, as appropriate.


14. If DMIGOP2=unit or MATOP4=unit is specified, an appropriate ASSIGNOUTPUT2 or ASSIGN OUTPUT4 statement must be present in the FileManagement Section (FMS) for the unit.

15. The creation of an external superelement using EXTSEOUT involves running anon-superelement NX Nastran job, with the following additional data:

• The data for the creation of the external superelement is specified by theEXTSEOUT case control entry.

• The boundary points of the external superelement are specified byASET/ASET1 bulk data entries.

• If the creation involves component mode reduction, the required generalizedcoordinates are specified using QSET/QSET1 bulk data entries. Theboundary data for the component mode reduction may be specified using theBNDFIX/BNDFIX1 and BNDFREE/BNDFREE1 bulk data entries (or theirequivalent BSET/BSET1 and CSET/CSET1 bulk data entries). (The defaultscenario assumes that all boundary points are fixed for the componentmode reduction.)

• The output for the external superelement is generated in the assembly job.This output consists of displacements, velocities, accelerations, SPC forces,MPC forces, grid point force balances, stresses, strains, and element forces.However, in order for this output to be generated in the assembly job, theoutput requests must be specified in the external superelement creation run.Normally, the only output requests for the external superelement that arehonored in the assembly job are those that are specified in the creationrun. There is, however, one important exception to this: the displacement,velocity, acceleration, SPC forces, and MPC forces output for the boundarygrid points as well as for all grid points associated with PLOTEL entries canbe obtained in the assembly job even if there is no output request specifiedfor these points in the creation run.

• If the assembly job involves the use of PARAM Bulk Data entries, thenthe following points should be noted:

– PARAM entries specified in the Main Bulk Data portion of the inputdata apply only to the residual and not to the external superelement.

– PARAM entries specified in the BEGIN SUPER portion of the BulkData for an external superelement apply only to the superelement.

– The most convenient way of ensuring that PARAM entries apply notonly to the residual but also to all external superelements is to specifysuch PARAM entries in Case Control, not in the Main Bulk Data. Thisis particularly relevant for such PARAMs as POST.


16. Output transformation matrices (OTMs) are generated for the following outputsrequested in the in external superelement run with EXTSEOUT:

• DISPLACEMENT

• VELOCITY

• ACCELERATION

• SPCFORCE

• MPCFORCE

• GPFORCE

• STRESS

• STRAIN

• FORCE

Only these external superelement results can be output in the system analysisrun. PARAM,OMID,YES is not applicable to the OTMs.

17. If a PARAM,EXTOUT or PARAM,EXTUNIT also exit, they will be ignored.The existence of the EXTSEOUT case control entry takes precedence overPARAM,EXTOUT and PARAM,EXTUNIT.

18. This capability is enabled in SOLs 101, 103, 105, 107-112, 114, 115, 118, 129,144-146, 159, 187, and 200. This capability is not enabled for thermal analyses.Superelement results can be recovered in the second step (i.e. superelementassembly, analysis, and data recovery) for SOLs 101, 103, 105-112, 129, 144-146,153, and 159.

19. The run creating the external superelement using this capability is not asuperelement run. No superelement designations are allowed (i.e. SUPER,SEALL, SESET, BEGIN SUPER, etc.).

Chapter

4 Contact Enhancements for Solutions101, 103, 111, 112

110 Stopping a Non-Converged Contact Solution

4.1 Stopping a Non-Converged Contact SolutionThe contact convergence tolerance is calculated by comparing changes in contactforces between the two contacting bodies. A contact problem is consideredconverged when

• The calculated convergence tolerance is less than the value of CTOL(definedon the BCTPARM bulk entry), and

• The number of contact changes from one iteration to the next is less than thevalue of NCHG (also on BCTPARM).

Contact solutions iterate until these conditions have been met, or the numberof iterations (MAXS field on BCTPARM) has been exceeded. In either case, thesolution continues, but produces a warning if convergence does not occur.

In this release, the new system cell 476 optionally forces a non-converged contactsolution to end with an error.

By default, system cell 476 = 0, and a warning is reported in the *.f06 file for thenon-converged contact solution, the solution continues and results creation occurs.

If system cell 476 = 1, a fatal error is reported in the *.f06 file for the non-convergedcontact solution, and the solution ends immediately with no results creation.

In most cases when a small percentage of contact elements fail to converge, theyare typically not sensitive to the quality of the stored results away from the contactregions.

4.2 Automatic/Adaptive Penalty Stiffness Options (BetaFunctionality)

The rate of convergence and to a lesser extent the accuracy of the contact solutionis influenced by the contact penalty factors PENN and PENT on the BCTPARMbulk entry. You can enter them as either 1/Length or Force/(Length x Area). Thedefaults for the penalty factors generally work well, but adjustments may benecessary in some cases.

Two new penalty stiffness options are being introduced in this release as betafunctionality:

• The PENAUTO field on the BCTPARM bulk entry tells the softwareto automatically calculate the normal and tangential penalty factors.If PENAUTO=1, the values for PENN and PENT are overwritten bysoftware-calculated values. By default, PENAUTO=0, and the values onPENN and PENT are used.

Penalty Factor Recommendations 111

• The PENADAPT field on the BCTPARM bulk entry tells the softwareto adaptively adjust the penalty factors at each contact iteration. IfPENADAPT=1, the software uses the average contact penetration at aniteration, along with the value defined on the new PENETFAC field, to scalethe penalty factors.

More specifically, a target penetration value (PTARGET) is calculated dependingon the value of PENETFAC, and the average depth of the elements in thecontact region.

PTARGET = PENETFAC x DAVG

where DAVG = the average depth of elements in the contact region.

At the end of each iteration, average contact penetrations (PAVG) are found,and a scale factor is calculated based on the ratio of PAVG and PTARGET.

SCALEFAC = PAVG / PTARGET

The normal and tangential penalty values are then scaled by the value ofSCALEFAC.

By default, PENADAPT=0, and the adaptive penalty factor calculation isturned off.

The default for PENETFAC is 1.0E-4. Values higher than the default may leadto higher penetrations and poor contact results while lower values could leadto increased number of contact iterations and difficulty with convergence.

The updated BCTPARM bulk entry is included at the end of this chapter.

4.3 Penalty Factor RecommendationsThe new automatic penalty options described in the previous section estimategeometry characteristics using element edge lengths in the vicinity of the contactregions. The software then uses the resulting estimated lengths to automaticallycalculate contact penalty stiffness values PENN and PENT. Since the lengthestimates are made without a full comprehension of the geometry characteristics,the automatic penalty options may be unsuccessful in some instances.

Below are some guidelines for manually setting the BCTPARM bulk entry inputsPENTYP, PENN and PENT, along with examples to help determine characteristicgeometry lengths.

PENTYP Recommendations

• Use PENTYP=1 when the elastic modulus (E) is fairly consistent for allmaterials in the model. The average modulus Eavg for all materials in the

112 Penalty Factor Recommendations

model should be representative of the stiffness in the vicinity of the contactconditions.

• Use PENTYP=2 if the average modulus Eavg is not representative of thestiffness in the vicinity of the contact conditions, or the elements used in thesource and target regions have vastly different stiffness properties.

When PENTYP=1, PENN and PENT have units of 1/(Length), and thefollowing is recommended.

• For solid element regions:

PENN and PENT=10/L

Where L is a length characteristic of the model.

• For shell element regions:

PENN and PENT=105t3/L4

where t and L are the thickness and characteristic length of the softer of the2 contacting surfaces, respectively.

When PENTYP=2, PENN and PENT have units of Force/(Length x Area),and the following is recommended.

• For solid element regions:

PENN and PENT=10*E/L

where E is the elastic modulus of the softer of the 2 contacting faces, and L isa length characteristic of the model.

• For shell element regions:

PENN and PENT=105Et3/L4

where E, t, and L are the elastic modulus, thickness, and characteristic lengthof the softer of the two contacting shell surfaces.

The following examples may help you determine a reasonable characteristic lengthfor penalty stiffness calculations. Flexibility exists in the definition of the length.

Penalty Factor Recommendations 113

Figure 4-1. Example 1 – Use the Radius of the Contacting Cylinder or theRadius plus the block Thickness as the Length

Figure 4-2. Example 2 – Use the Radius of the Inner or Outer Cylinder asthe Length

114 Penalty Factor Recommendations

Figure 4-3. Example 3 – Use the Inner or Outer Radius of the Wheel asthe Length

Figure 4-4. Example 4 – Use the Radius or Diameter of the Arch as theLength

Contact Conditions with the Iterative Solver (Beta Functionality) 115

Figure 4-5. Example 5 – Use the Length of One of the Cantilever Shells asthe Length

4.4 Contact Conditions with the Iterative Solver (BetaFunctionality)

Contact conditions can now be included when solving a model with the elementiterative solver. This capability is still in the beta phase and is not fully supported,but you can use it if you would like to evaluate the capability. Two restrictionsexist. One is that a bolt pre-load definition cannot be combined with a contactdefinition when solving with the element iterative solver. The other is that GLUEdefinitions cannot be combined with a contact definition when solving with theelement iterative solver.

The “element” based iterative solver was introduced in NX Nastran 2 for the linearstatics solution, SOL 101. Unlike the existing “global” iterative solver where thesystem stiffness matrix is assembled, the element iterative solution works entirelyfrom the element matrices. Use of the element iterative solver yields greaterefficiency and yields run time improvements typically of 4x to 6x as compared tothe global iterative solver. In addition, a significant reduction in disk space is alsorealized. The best performance gain will be seen with models composed of mostlysolid tetra elements.

To use the element based iterative solver for a contact solution, add the keywordELEMITER=YES and SYSTEM(395)=2 to the Nastran card. This typicallyappears as:

NASTRAN ITER=YES, ELEMITER=YES, SYSTEM(395)=2 $

Note that the ITER, ELEMITER and SYSTEM(395)=2 inputs are all required.

For more information on the Iterative Solutions, see:

• The chapter “Iterative Solution of Systems of Linear Equations” in the NXNastran Numerical Methods User’s Guide

116 Contact Conditions with the Iterative Solver (Beta Functionality)

• “ITER” in the NX Nastran Quick Reference Guide

Updated BCTPARM Bulk Entry 117Surface-to-Surface Contact Parameters (SOLs 101, 103, 111 and 112).

4.5 Updated BCTPARM Bulk EntryBCTPARM Surface-to-Surface Contact Parameters (SOLs 101, 103, 111and 112).

Control parameters for the surface-to-surface contact algorithm.

Format:

1 2 3 4 5 6 7 8 9 10

BCTPARM CSID Param1 Value1 Param2 Value2 Param3 Value3

Param4 Value4 Param5 Value5 -etc-

Example:

BCTPARM 1 PENN 1.0 CTOL 0.001

Fields:

Field Contents

CSID Contact set ID. Parameters defined in this command apply tocontact set CSID defined by a BCTSET entry. (Integer > 0)

PARAMi Name of the BCTPARM parameter. Allowable names are given inthe parameter listing below. (Character)

VALUEi Value of the parameter. See Table 4-1 for the parameter listing.(Real or Integer)

Table 4-1. BCTPARM Parameters

Name Description

PENN Penalty factor for normal direction. (Default=10.0) See Remark 1.

PENT Penalty factor for transverse direction. (Default=1.0) See Remark 1.

PENTYP Changes how contact element stiffness is calculated (Default=1).See Remark 1

1- PENN and PENT are entered as units of 1/Length.

2 - PENN and PENT are entered as units of Force/(Length x Area).

118 BCTPARMSurface-to-Surface Contact Parameters (SOLs 101, 103, 111 and 112).


Name Description

PENAUTO Activates automatic calculation of normal and tangential penaltyfactors.

0 – PENN and PENT will be used. (Default)

1 – Automatic solution calculation of PENN and PENT.

PENADAPT Activates adaptive stiffness adjustment. See Remark 2.

0 – No adaptive adjustment. (Default)

1 – Adaptively adjusts contact stiffness.

PENETFAC Penetration factor for adaptive penalty stiffness adjustment. SeeRemark 2.

Default = 1e-4. Active when PENADAPT=1.

CTOL Contact force convergence tolerance. (Default=0.01)

MAXF Maximum number of iterations for force a loop. (Default=10)

MAXS Maximum number of iterations for a status loop. (Default=20)

NCHG Allowable number of contact changes for convergence.(Default=0.02). See Remark 3.

MPER Minimum contact set percentage. (Default=100)

SHLTHK Shell thickness offset flag.

0 - Includes half shell thickness as surface offset. (Default)

1 - Does not include thickness offset.

RESET Flag to indicate if the contact status for a specific subcase is to startfrom the final status of the previous subcase

0 - Starts from previous subcase. (Default)

1 - Starts from initial state.

BCTPARM 119Surface-to-Surface Contact Parameters (SOLs 101, 103, 111 and 112).


Name Description

AVGSTS Determines the averaging method for contact pressure/tractionresults.

0 - The averaging of Pressure/Traction values for a contact gridwill include the results from ALL contact elements attached to thegrid regardless of whether they are active or inactive in the contactproblem (Default).

1 - The averaging of the Pressure/Traction values for a contact gridwill exclude those contact elements which are not active in thecontact solution and thus have a zero Pressure/Traction value.

INIPENE Use when the goal is for a pair of contact regions to be initiallytouching without interference, but due to the faceted nature of finiteelements around curved geometry, some of the element faces mayhave a slight gap or penetration.

0 or 1 - Contact is evaluated exactly as geometry is modeled. Nocorrections will occur for gaps or penetrations (Default).

2 - Penetrations will be reset to a new initial condition in whichthere is no interference.

3 - Gaps and penetrations are both reset to a new initial conditionin which there is no interference.

REFINE Determines if the mesh on the source region is refined during thecontact solution.

0 - Do not refine the contact source region based on target surfacedefinition.

1 - Refine the contact source region based on target surfacedefinition (default).



Name Description

INTORD Determines the number of contact evaluation points for a singleelement face on the source region. The number of contact evaluationpoints is dependent on the value of INTORD, and on the type ofelement face. See the table in Remark 4 for specific values.

1 – The reduced number of contact evaluation points is used.

2 – Use an increased number of contact evaluation points (default).

3 – Use a high number of contact evaluation points.

ZOFFSET Determines if the shell element z-offset is included in the contactsolution.

0 - Includes the shell z-offset when determining the contact surfaces(Default).

1 - Does not include the shell z-offset when determining the contactsurfaces.

CSTRAT Prevents all of the contact elements from becoming inactive. SeeRemark 5.

0 - All contact elements can become inactive (Default).

1 - The software will reduce the likelihood of all of the contactelements becoming inactive.

See “Contact Control Parameters – BCTPARM” in the NX Nastran User’s Guide formore information on the BCTPARM options.

Remarks:

1. The penalty stiffness between contact surfaces is obtained from the penalty factorinputs PENN, PENT and PENTYP. When PENTYP=1 (default), PENN andPENT have units of 1/(Length), and the contact element stiffness is calculatedby K = e*E*dA where e represents PENN or PENT, E is an average modulus(averaged over the entire model), and dA is area. A physical interpretation isthat it is equivalent to the axial stiffness of a rod with area dA, modulus E,and length 1/e.

When PENTYP=2, PENN and PENT become a spring rate per areaForce/(Length x Area), and the contact element stiffness is calculated as K=e*dA.

BCTPARM 121Surface-to-Surface Contact Parameters (SOLs 101, 103, 111 and 112).

The spring rate input is a more explicit way of entering contact stiffness since itis not dependent on the average modulus.

The defaults for the penalty factors generally work well, but in the eventthat meshes have very large or very small edge lengths, adjustments may benecessary. See “Tips for Setting PENN and PENT” in the NX Nastran User’sGuide for tips on adjusting penalty factors.

2. When PENADAPT is set to “1”, the software will use the average contactpenetration at an iteration along with the value defined on the PENETFACfield to scale the penalty factors. More specifically, a target penetration value(PTARGET) is calculated depending on the value of PENETFAC, and the averagedepth of the elements in the contact region.

PTARGET = PENETFAC x DAVG

where DAVG = the average depth of elements in the contact region.

At the end of each iteration, average contact penetrations (PAVG) are found, anda scale factor is calculated based on the ratio of PAVG and PTARGET.

SCALEFAC = PAVG / PTARGET

The normal and tangential penalty values are then scaled by the value ofSCALEFAC.

The default for PENETFAC is 1.0E-4. Values higher than the default may leadto higher penetrations and poor contact results while lower values could lead toincreased number of contact iterations and difficulty with convergence.

3. If NCHG is a real number and is < 1.0, the software treats it as a percentage ofthe number of active contact elements in each outer loop of the contact algorithm.The number of active contact elements is evaluated at each outer loop iteration.

If NCHG is an integer ≥1, the value defines the allowable number of contactchanges.

If NCHG = 0, no contact status changes can exist.

4. A higher number of contact evaluation points can be used to increase theaccuracy of a contact solution. Inaccuracies sometimes appear in the formof nonuniform contact pressure and stress results. There may be a penaltyassociated with using more evaluation points since the time for a contact problemto converge may be longer. The table below shows how the number of contactevaluation points is dependent on the element type, and how it can be adjustedusing the INTORD option. The “Face Type” column applies to shell elements,and to the solid element with the associated face type.

Number of Contact Evaluation Points


Face Type INTORD=1 INTORD=2 INTORD=3Linear Triangle 1 3 7Parabolic Triangle 3 7 12Linear Quad 1 4 9Parabolic Quad 4 9 16

5. Under certain conditions, all of the contact elements could become inactive whichmay lead to singularities. Setting the parameter CSTRAT=1 will reduce thelikelihood of all contact elements becoming inactive.

Chapter

5 Surface-to-Surface Glue Enhancements

124 Glue Refinement Supported on Shell Element Regions

5.1 Glue Refinement Supported on Shell Element RegionsThe number of glue elements which are created and their distribution willdetermine the accuracy of the glued interface. INTORD and REFINE, are availableon the BGPARM bulk entry to improve the accuracy of the glue solution. Thenumber of locations where normals are projected (glue points) from the sourceregion is dependent on the value assigned to the INTORD parameter, and on theelement face type.

INTORD is supported by both shell and solid element regions, yet previously,the REFINE field on BGPARM was reserved for only solid element regions. NowREFINE is also supported by both shell and solid element regions.

REFINE will increase the number of glue points by refining the mesh on the sourceregion. The resulting refinement on the source region is more consistent with thetarget side, which gives a better distribution of glue elements. The refined gridsand elements are only used during the solution.

By default, REFINE=1 and mesh refinement occurs. REFINE=0 will turn off therefinement capability.

5.2 New Weld-Like Glue MethodA surface-to-surface glue condition on non-coincident shell or solid faces can resultin artificial rotational energy being introduced into the solution. Generally, theproblem is that the spring-like glue elements do not transfer moments at the glueinterface when glued faces are non-coincident and/or loads are not normal to theglued faces. This is particularly noticeable in a normal mode solution when modesare found that contain an artificial rotational energy due to the glue condition.

Now, a weld-like glue algorithm is available which eliminates the artificialrotational energy. When the new field GLUETYPE on the BGPARM bulk entry isassigned to “2” (default), the weld-like algorithm is used. GLUETYPE=1 requeststhe original, spring-like glue algorithm. The weld-like glue is the default, sinceit does transfer moments at the glue interface, and represents the connectionstiffness more accurately than the spring-like glue in most situations.

Each GLUETYPE has unique penalty factor inputs on the BGPARM bulk entry.Their inputs and units are as follows.

GLUETYPE=1The glue penalty stiffness is defined by PENN and PENT.(SOL 153 - Heat transfer analysis always uses GLUETYPE=1.)

Automatic Penalty Stiffness Option (Beta Functionality) 125

PENTYP=1PENN and PENT have the units of 1/Length.(SOL 153 only uses PENN.)Structural solutions: PENN and PENT have theunits of Force/(Length x Area).PENTYP=2 SOL 153: PENN has the units of (thermalconductivity*length)/area.

GLUETYPE=2The glue penalty stiffness is defined by the new PENGLUEpenalty factor (default=100).

PENTYP=1 PENGLUE is a unitless value (glue stiffness scalefactor).

PENTYP=2 PENGLUE has the units of F/L2.

For glued coincident faces, there is little flexibility between the faces with defaultpenalty factors. Regardless of which GLUETYPE is used, the glue conditioncreated between non-coincident faces will not usually produce a local stiffness asaccurate as using a conventional finite element for the connection. The flexibilityin the glue condition will depend on the GLUETYPE used, and the value of thepenalty factors. The weld-like glue stiffness is usually high with the defaultpenalty value. This is especially true for linear shell elements. Reducing thepenalty factor (PENGLUE) to 1.0 will produce a more flexible connection. If youhave non-coincident faces and the glue joint flexibility is important, then it isrecommended that you model this connection with conventional finite elements.

5.3 Automatic Penalty Stiffness Option (BetaFunctionality)

The following new penalty stiffness option is being introduced in this release asbeta functionality.

A new option has been created to have the software automatically calculate thenormal and tangential penalty factors. By setting the new PENAUTO field on theBGPARM bulk entry to “1”, the values for PENN and PENT will be overwritten bysoftware calculated values. By default, PENAUTO=0, and the values on PENNand PENT are used.

The updated BGPARM bulk entry is included at end of the chapter.

126 Updated BGPARM Bulk EntryGlue Parameters

5.4 Updated BGPARM Bulk EntryBGPARM Glue Parameters

Control parameters for the glue algorithm.

Format:

1 2 3 4 5 6 7 8 9 10

BGPARM GSID Param1 Value1 Param2 Value2 –etc–

Example:

BGPARM 4 INTORD 2

Fields:

Field Contents

GSID Glue set ID. Parameters defined in this command apply to glue setGSID defined by a BGSET entry. (Integer > 0)

PARAMi Name of the BGPARM parameter. Allowable names are given in theparameter listing below. (Character)

VALUEi Value of the parameter. See below for the parameter listing. (Realor Integer)

Table 5-1. BGPARM Parameters

Name Description

GLUETYPE Selects the glue formulation. (Default=2) See Remark 1.

1 - Normal and tangential springs will be used to define theconnections.

2 - A “weld like” connection will be used to define the connections.

PENTYP Changes how glue element stiffness and “conductance” arecalculated. (Default=1) See Remark 1.

PENN Penalty factor for normal direction when GLUETYPE=1.(Default=100) See Remark 1.

BGPARM 127Glue Parameters

Table 5-1. BGPARM Parameters

Name Description

PENT Penalty factor for transverse direction when GLUETYPE=1.(Default=100) See Remark 1.

PENGLUE Penalty factor when GLUETYPE=2. (Default=100) See Remark 1.

INTORD Determines the number of glue points for a single element face onthe source region.

1 - Low order

2 - Medium order (default)

3 - High order

REFINE Determines if the mesh on the source region is refined during theglue solution (not supported with shell elements).

0 - Do not refine the glue source region based on target surfacedefinition.

1 - Refine the glue source region based on target surface definition(default).

PENAUTO Activates automatic calculation of normal and tangential penaltyfactors.

0 – PENN and PENT will be used. (Default)

1 – PENN and PENT are calculated during the solution.

Remarks

1. Each GLUETYPE has unique penalty factor inputs. Their inputs and unitsare as follows.

GLUETYPE=1The glue penalty stiffness is defined by PENN and PENT.(SOL 153 - Heat transfer analysis always uses GLUETYPE=1.)

128 BGPARMGlue Parameters

Structural solutions: PENN and PENT haveunits of 1/(length), and the glue elementstiffness is calculated by K = e*E*dA where erepresents PENN or PENT, E is an averagemodulus (averaged over the entire model), anddA is area. A physical interpretation is that itis equivalent to the axial stiffness of a rod witharea dA, modulus E, and length 1/e.

PENTYP=1 SOL 153: PENT is ignored. PENN has theunits of 1/(length), and “conductance” at theglue connection is calculated as C = e*kavg*dA,where e represents PENN, kavg is an averageof the thermal conductivity (k) values for allMAT4 entries, and dA is area. A physicalinterpretation is that it is equivalent to theaxial "conductance" of a rod with area dA,conductivity kavg, and length 1/e.Structural solutions: PENN and PENT becomea spring rate per area Force/(Length x Area),and the glue element stiffness is calculatedas K=e*dA. The spring rate input is a moreexplicit way of entering glue stiffness since it isnot dependent on the average modulus.PENTYP=2SOL 153: PENT is ignored. PENN has theunits of (thermal conductivity*length)/area,and the “conductance” at the glue connection iscalculated as C = e*dA. Another term for e isheat flux.

GLUETYPE=2 The glue penalty stiffness is defined by the PENGLUE penaltyfactor (default=100).

PENTYP=1 PENGLUE is a unitless value (glue stiffnessscale factor).Structural

solutions: PENTYP=2 PENGLUE has the units of F/L2.SOL 153: Always uses GLUETYPE=1.

2. BGPARM is not supported in SOL 601, although glue definitions (BGSET) aresupported.

Chapter

6 Element Additions

130 Pyramid Element Enhancement

6.1 Pyramid Element EnhancementCertain modeling features are best meshed with tetrahedral elements whilehexahedral elements are preferred where possible. As a result, there is a needto transition from either linear or parabolic tetrahedral to linear or parabolichexahedral elements. The pyramid element can be used to make this meshtransition.

The pyramid element (CPYRAM), which was introduced in NX Nastran 6.0 forsolutions 601 and 701, is now supported in solutions 101, 103, 105, 106 (linearonly), 107-112, 114, 115, 116, 118, 144, 145, 146, 153, 159, 187 and 200. It can bedefined as a mixed-order element (variable 5 to 13 grids) in all supported solutions,except for solutions 601 and 701 which only support a 5–grid (linear) or 13–grid(parabolic) definition.

The pyramid element has been added to the solid element verification test results,and are included in the Pyramid Element Verification Test Results chapter in thisrelease guide. In addition, the following documentation pertaining to the CPYRAMelement has been updated, and is included in the following sections:

• CPYRAM bulk entry

• PSOLID bulk entry

• PLOAD4 bulk entry

• CHBDYE bulk entry

• GEOMCHECK executive control statement

• Element stress/strain item codes

Generally, the CPYRAM element supports the same inputs as the CHEXAelement. Note that the following inputs have a specific list of supported elementsdocumented in the version 6.0 Quick Reference Guide, and are supported by theCPYRAM: ELSUM case control command, COUPMASS parameter, BSURFS bulkentry, EBDSET bulk entry, and the MAT1 bulk entry.

These inputs are not supported by the CPYRAM: SET OUTPUT(PLOT) casecontrol, DTI,INDTA bulk entry, and the RSSCON bulk entry.

Element Library Information for Pyramid

Five-Sided Solid Element (CPYRAM)

The CPYRAM has five corner grid points and up to 13 grid points if you includethe eight optional midside grid points.

Pyramid Element Enhancement 131

The CPYRAM element is commonly used to model transitions from either linearor parabolic tetrahedral to linear hexahedral elements (although parabolichexahedral elements could be used as well). It is needed because certainmodeling features are best meshed with tetrahedral elements, while hexadedralelements are preferred where possible. NX Nastran calculates element stresses

at the element’s center and gauss points, thenextrapolates them out to the corner grid points. The element’s connection geometryis shown in the following figure.

You can delete any or all of the midside nodes for the CPYRAM element. Use the13–noded CPYRAM in areas where accurate stress data recovery is required.

CPYRAM Format

1 2 3 4 5 6 7 8 9 10

CPYRAM EID PID G1 G2 G3 G4 G5 G6

G7 G8 G9 G10 G11 G12 G13

The format of the CPYRAM element entry is as follows:

Field ContentsEID Element identification number. (Integer > 0)

PID Property identification number of a PSOLID entry. (Integer > 0)Gi Identification numbers of connected grid points. (Integer ≥ 0 or

blank)

Grid points G1 through G4 define a quadrilateral face. The other four faces aretriangles. G5 is the vertex and must be opposite with the quadrilateral face. The

132 CPYRAMFive-Sided Solid Element Connection

midside nodes, G6 to G13, are optional. If the ID of the midside node is left blankor set to zero, the equations of the element are adjusted to give correct resultsfor the reduced number of connections. Corner grid points cannot be deleted.Components of stress are output in the material coordinate system. You define thematerial coordinate system on the PSOLID entry.

Updated CPYRAM Bulk Entry

CPYRAM Five-Sided Solid Element Connection

Defines the connection of the five-sided solid element with five to thirteen gridpoints.

Format:

1 2 3 4 5 6 7 8 9 10CPYRAM EID PID G1 G2 G3 G4 G5 G6

G7 G8 G9 G10 G11 G12 G13

Figure 6-1. CPYRAM Element Connection

Example:

CPYRAM 111 203 31 32 33 34 35 36

37 38 39 40 41 42 43

CPYRAM 133Five-Sided Solid Element Connection

Fields:

Field Contents

EID Element identification number. (Integer > 0)

PID Property identification number of a PSOLID entry. (Integer > 0;Default=EID)

Gi Grid point identification numbers of connected points. (Uniqueintegers > 0)

Remarks:

1. Element identification numbers should be unique with respect to all otherelement identification numbers.

2. Grid points G1 through G4 must be given in consecutive order about onequadrilateral face. The other four faces are triangles. G5 is the vertex and mustbe opposite with the quadrilateral face.

3. The edge points G6 to G13 are optional. Any or all of them may be deleted. Ifthe ID of any edge connection point is left blank or set to zero, the equationsof the element are adjusted to give correct results for the reduced numberof connections. Corner grid points cannot be deleted. The element is anisoparametric element in all cases.

4. Components of stress are output in the material coordinate system.

5. The CPYRAM element coordinate system is the same as the basic coordinatesystem.

6. It is recommended that the edge points be located within the middle third ofthe edge.

7. Only h-version formulation is available; p-version formulation is not supported.

8. The CPYRAM element is also not supported in SOL 106 and 129 (which includeshyperelastic). The CPYRAM element will behave linearly with SOL 106 and 129.

9. By default, all eight edges of the element are considered straight unless any ofG6 through G13 is specified.

134 PSOLIDProperties of Solid Elements

Remarks related to SOLs 601 and 701:

1. For SOL 601, only elements with 5 or 13 grid points are allowed, i.e., either alledge points G6 to G13 are specified or no edge points are specified. For SOL 701,only elements with 5 grid points are allowed.

2. For SOL 601, when ELCV=1 is specified in NXSTRAT (see Remark 2 (SOL 601)in CHEXA entry), 13-node CPYRAM elements will be converted to 14-nodepyramid elements (1 additional node on the centroid of the quadrilateral face ofthe element).

Updated PSOLID Bulk Entry

PSOLID Properties of Solid Elements

Defines the properties of solid elements (CHEXA, CPENTA, CPYRAM, CQUADX4,CQUADX8, CTETRA, CTRAX3, and CTRAX6 entries).

Format:

1 2 3 4 5 6 7 8 9 10PSOLID PID MID CORDM IN STRESS ISOP FCTN

Example:PSOLID 2 100 6 TWO GRID REDUCED

Fields:

Field Contents

PID Property identification number. (Integer > 0)

MID Identification number of a MAT1, MAT3, MAT4, MAT5, MAT9, orMAT10 entry. (Integer > 0) See Remark 2.

CORDM Identification number of the material coordinate system. SeeRemarks 3, 4, and 6. (Integer; Default = 0, which is the basiccoordinate system; see Remark 3 . )

IN Integration network. See Remarks 7, 8, 9, and 11. (Integer,Character, or blank)

STRESS Location selection for stress output. See Remarks 6, 10, and 11.(Integer, Character, or blank)

PSOLID 135Properties of Solid Elements

Field Contents

ISOP Integration scheme. See Remarks 7, 8, 9, and 11. (Integer,Character, or blank)

FCTN Fluid element flag. (Character: “PFLUID” indicates a fluid element,“SMECH” indicates a structural element; Default = “SMECH.”)

Remarks:

1. PSOLID entries should have unique identification numbers with respect to allother property entries.

2. Isotropic (MAT1 or MAT4), axisymmetric solid orthotropic (MAT3), anisotropic(MAT5 or MAT9), fluid (MAT10) material properties may be referenced. IfFCTN=“PFLUID”, then MID must reference a MAT10 entry.

3. See the CHEXA, CPENTA, CPYRAM or CTETRA entry for the definition ofthe element coordinate system. The material coordinate system (CORDM)may be the basic system (0 or blank), any defined system (Integer > 0), or theelement coordinate system (-1). The default value for CORDM is zero unlessit is overridden by the NASTRAN statement with the CORDM keyword. See“nastran Command and NASTRAN Statement” .

4. If MID references a MAT9 entry, then CORDM defines the material propertycoordinate system for Gij on the MAT9 entry.

5. The material coordinate system on the CQUADX4, CQUADX8, CTRAX3, andCTRAX6 elements is defined by “TH” on the element definition, and not byCORDM.

6. Components of stress are output in the material coordinate system except:a. Stress output labeled "NONLINEAR STRESSES", which is output in theelement coordinate system.b. Hyperelastic element stress, which is always output in the basic coordinatesystem, including when in the stress output labeled "NONLINEAR STRESSES".See SOL 601/701 remarks 1 and 4 for Advanced Nonlinear exceptions.

7. For CHEXA and CPENTA elements with no midside nodes, reduced shearintegration with bubble functions (ISOP = blank or “REDUCED” and IN = blankor “BUBBLE”) is the default. This is recommended because it minimizes shearlocking and Poisson’s ratio locking and does not cause modes of deformation thatlead to no strain energy. The effects of using nondefault values are as follows:

a. IN = “THREE” or 3 produces an overly stiff element.


b. If IN = “TWO” or 2 and the element has midside nodes, modes of deformationmay occur that lead to no strain energy.

c. Standard isoparametric integration (ISOP = “FULL” or 1 and IN = “TWO” or2; or “THREE” or 3) produces an element overly stiff in shear. This type ofintegration is more suited to nonstructural problems.

8. IN = “BUBBLE” is not allowed for CTETRA elements or for CHEXA andCPENTA elements with midside nodes.

9. For CTETRA and fluid elements (FCTN = “PFLUID”), standard isoparametricintegration (ISOP = “FULL” or 1 and IN = “TWO” or 2; or “THREE” or 3) is thedefault and the only option available.

10. Stress output may be requested at the Gauss points (STRESS = “GAUSS” or 1) ofCHEXA and CPENTA elements with no midside nodes. Gauss point output isavailable for the CTETRA element with or without midside nodes.

11. The following tables indicate the allowed options and combination of options. Ifa combination not found in the table is used, then a warning message will beissued and default values will be assigned for all options.

12. The gauss point locations for the solid elements are documented in “Elements forNonlinear Analysis” in the NX Nastran Basic Nonlinear Analysis User’s Guide.


1. MID is the identification number of a MAT1, MAT9, or MATG entry for 3D solidelement and a MAT1 or MAT3 entry for axisymmetric element. Note that whenMID references a MAT1 entry, CORDM is ignored, and stresses are output inthe basic coordinate system.

2. For geometric nonlinear analysis, it is recommended not to use incompatiblemodes by setting IN=2 or 3. If bending behavior is significant, it is highlyrecommended that elements with midside nodes be used.

3. For SOL 701, IN=2 is the default, i.e. incompatible modes are not used bydefault for SOL 701. To use incompatible modes in SOL 701, IN=BUBBLE mustbe specified.

4. By default, nonlinear stress results are output in the element coordinate system.However, ELRESCS=1 may be specified in NXSTRAT entry to request outputof nonlinear stress results in the material property coordinate system withCORDM=-1 being treated as basic coordinate system. Hyperelastic elementstress is always output in the basic coordinate system.

5. STRESS is ignored. Stresses and strains are output at grid points of element.


6. ISOP is ignored. 2x2x2 integration (and equivalent) is used for elements withno midside nodes. 3x3x3 integration (and equivalent) is used for elements withmidside nodes.

7. FCTN is not supported.

Table 6-1. CHEXA Entry Options

CHEXA Integration IN STRESS(Default:GRID)

ISOP (Default: SeeRemarks 5 and 7.)

NonlinearCapability

2x2x2 ReducedShear with BubbleFunction (default)

BUBBLE orBlank or 0(Default)

2x2x2 ReducedShear Only

Blank or REDUCED(Default*)

Yes

2x2x2 StandardIsoparametric

TWO or 2

Blank or GRIDorGAUSS or 1

FULL or 1


Blank or REDUCED

8 Node


THREE or 3 Blank or GRIDFULL or 1

No


Blank or REDUCED


TWO or 2FULL or 1

3x3x3 ReducedShear Only(default)

Blank or REDUCED(Default*)

9 -20 Node

3 x3x3 StandardIsoparametric

Blank orTHREE or3 (Default)

Blank or GRID

FULL or 1

No

Reduced (p-order)Bubble

0 or 1 0

Bubble, P+ISOPIntegration

1p-elements

No Bubble,P+ISOPIntegration

2 or 3

Not applicable

−10 ≤ ISOP ≤ 10

No

* REDUCED is the default only for structural elements (FCTN=“SMECH”).


Table 6-2. CPENTA Entry Options

CPENTA Integration INSTRESS(Default:GRID)


NonlinearCapability

2x3 ReducedShear withBubble Function(Default)

Blank or 0or BUBBLE(Default)

2x3 ReducedShear Only

Blank orREDUCED(Default*)

2x3 StandardIsoparametric

TWO or 2

GAUSS or 1 orBlank or GRID

FULL or 1

Yes


Blank orREDUCED

6 Node


THREE or 3 Blank or GRIDFULL or 1

No


Blank orREDUCED


TWO or 2FULL or 1

3x7 ReducedShear Only(default)

Blank orREDUCED(Default*)

7-15 Node


Blank orTHREE or 3(Default)

Blank or GRID

FULL or 1

No

2x3 for p=1, 1,13x7 for p=2, 2,2(p+1)x(p) forall other

0 or 1 0

2x3 for p=1, 1,13x7 for p=2, 2,2

0

3x7 for p=1, 1, 1 1

p-elementsBubbleFunction

(p+ISOP+1)x(p+ISOP) for allother

1

−10 ≤ ISOP ≤ −1or2≤ ISOP ≤ 10

2x3 for p=1, 1,13x7 for p=2, 2,2

0p-elementsStandardIsopara-metric(no bubble

2 or 3

Not applicable No


Table 6-2. CPENTA Entry Options

CPENTA Integration INSTRESS(Default:GRID)


NonlinearCapability

3x7 for p=1, 1, 1 1

function) (p+ISOP+1)x(p+ISOP) for allother

−10 ≤ ISOP ≤ −1or2≤ ISOP ≤ 10

Note

REDUCED is the default only for structural elements (FCTN=“SMECH”).

Table 6-3. CPYRAM Entry Options

IntegrationCPYRAM

Structural Heat TransferIN

STRESS(Default:GRID)

ISOP NonlinearCapability

2x2x2StandardIsoparametric

Blankor 0(Default)

5 Node3x3x3StandardIsoparametric


1 (SeeNote 2below.)


Blankor 0(Default)6–13

Node 3x3x3StandardIsoparametric


1 (SeeNote 2below.)


Blank or 0 (Default)or 2 (See Note 1below.)

No

Note 1: The default value of Blank or 0 uses a standard formulation. A value of 2specifies the B-BAR option for nearly incompressible materials.

Note 2: For CPYRAM, IN = 1 produces an overly stiff element.


Table 6-4. CTETRA Entry Options

CTETRA Integration IN STRESS(Default:GRID) ISOP Nonlinear

Capability

1-PointStandardIsoparametric(Default)

Blank orTWO or 2(Default)


Yes

4 Node

5-PointStandardIsoparametric

THREE or 3 Blank or GRID

Blank or FULL

No

5—10 Node 5-PointStandardIsoparametric

Blank orTHREE or3 (Default)

GAUSS or1orBlank orGRID

Blank or FULL No

1-Point;P=1,1,15-Point;P=2,2,2P+1Cubic Point;P>2

0

5-Point;P=1,1,1P+1Cubic for allother

1p-elements

P+ISOP Cubic

0 or 1 Not applicable

−10 ≤ ISOP ≤ −1or2= ISOP ≤ 10

No

Table 6-5. Axisymmetric Solid Entry Options for CQUADX4

Integration IN STRESS (default=GRID) Nonlinear Capability

Full Integration usinginternal shape functions

Blank or 0 (default) No

Full Integration withoutusing internal shapefunctions

1 No

Mean Dilatationalformulation

2

Blank or GRID (corner)or

Gauss or 1

No

PLOAD4 141Pressure Load on Surface and Faces of Solid Elements

Table 6-6. Axisymmetric Solid Entry Options for CQUADX8, CTRAX3, andCTRAX6

Integration IN STRESS (default=GRID) Nonlinear Capability

Full Integration Blank or 0 (default) No

Mean Dilatationalformulation

2

Blank or GRID (corner)or

Gauss or 1 No

Updated PLOAD4 Bulk Entry

PLOAD4 Pressure Load on Surface and Faces of Solid Elements

Defines a pressure load on a face of a CHEXA, CPENTA, CTETRA, CPYRAM,CTRIA3, CTRIA6, CTRIAR, CQUAD4, CQUAD8, or CQUADR element.

Format:

1 2 3 4 5 6 7 8 9 10PLOAD4 SID EID P1 P2 P3 P4 G1 G3 or G4

CID N1 N2 N3

Example:PLOAD4 2 1106 10.0 8.0 5.0 48

6 0.0 1.0 0.0

Alternate Format and Example

(See Remark 8 ):

PLOAD4 SID EID1 P1 P2 P3 P4 “THRU” EID2

CID N1 N2 N3

PLOAD4 2 1106 10.0 8.0 5.0 THRU 1143

6 0.0 1.0 0.0

Fields:

Field Contents

SID Load set identification number. (Integer > 0)

142 PLOAD4Pressure Load on Surface and Faces of Solid Elements

Field Contents

EID EID1EID2

Element identification number. (Integer > 0; for the “THRU”option, EID1 < EID2)

P1, P2, P3,P4

Load per unit surface area (pressure) at the corners of the face ofthe element. (Real or blank; Default for P2, P3, and P4 is P1.)

G1 Identification number of a grid point connected to a corner of theface. Required data for solid elements only. (Integer > 0 or blank)

G3 For CHEXA, CPYRAM, or CPENTA quadrilateral faces, G3 isthe identification number of a grid point connected to a cornerdiagonally opposite to G1. Required for quadrilateral faces ofCHEXA, CPYRAM and CPENTA elements only.

For CPYRAM element triangle faces, G1 and G3 are adjacentcorner nodes on the quadrilateral face, and the load is applied onthe triangular face which includes those grids.

For CPENTA element triangle faces, G3 must be omitted.

G4 Identification number of the CTETRA grid point located at thecorner; this grid point may not reside on the face being loaded.This is required data and is used for CTETRA elements only.(Integer > 0)

CID Coordinate system identification number. See Remark 2 . (Integer≥ 0; Default = 0)

N1, N2, N3 Components of vector measured in coordinate system defined byCID. Used to define the direction (but not the magnitude) of theload intensity. See Remark 2 . (Real)

Remarks:

1. In the static solution sequences, the load set ID (SID) is selected by the CaseControl command LOAD. In the dynamic solution sequences, SID must bereferenced in the LID field of an LSEQ entry, which in turn must be selected bythe Case Control command LOADSET.

2. The continuation entry is optional. If fields 2, 3, 4, and 5 of the continuationentry are blank, the load is assumed to be a pressure acting normal to the face.If these fields are not blank, the load acts in the direction defined in these fields.Note that if CID is a curvilinear coordinate system, the direction of loading mayvary over the surface of the element. The load intensity is the load per unit ofsurface area, not the load per unit of area normal to the direction of loading.

PLOAD4 143Pressure Load on Surface and Faces of Solid Elements

3. For the faces of solid elements, the direction of positive pressure (defaultedcontinuation) is inward. For triangular and quadrilateral faces, the loadintensity P1 acts at grid point G1 and load intensities P2, P3, (and P4) act atthe other corners in a sequence determined by applying the right-hand ruleto the outward normal.

4. For plate elements, the direction of positive pressure (defaulted continuation) isin the direction of positive normal, determined by applying the right-hand ruleto the sequence of connected grid points. The load intensities P1, P2, P3, (andP4) act respectively at corner points G1, G2, G3, (and G4) for triangular andquadrilateral elements. (See plate connection entries.)

5. If P2, P3, and P4 are blank fields, the load intensity is uniform and equal to P1.P4 has no meaning for a triangular face and may be left blank in this case.

6. Equivalent grid point loads are computed by linear or bilinear interpolationof load intensity followed by numerical integration using isoparametric shapefunctions. Note that a uniform load intensity will not necessarily result in equalequivalent grid point loads.

7. G1 and G3 are ignored for CTRIA3, CTRIA6, CTRIAR, CQUAD4, CQUAD8,and CQUADR elements.

8. The alternate format is available only for CTRIA3, CTRIA6, CTRIAR, CQUAD4,CQUAD8, and CQUADR elements. The continuation entry may be used in thealternate format.

9. For triangular faces of CPENTA elements, G1 is an identification number of acorner grid point that is on the face being loaded and the G3 or G4 field is leftblank. For faces of CTETRA elements, G1 is an identification number of a cornergrid point that is on the face being loaded and G4 is an identification numberof the corner grid point that is not on the face being loaded. Since a CTETRAhas only four corner points, this point G4 will be unique and different for each ofthe four faces of a CTETRA element.

10. All referenced elements must exist (closed list) for residual only runs and arenot required to exist (open list) for superelement runs; and they cannot behyperelastic for either.

11. If fields 3 through 5 of the continuation entry are not blank, the load is assumedto have a fixed direction. If fields 2 through 5 of the continuation entry are leftblank, the load is assumed to be a pressure load. In this case, follower forceeffects are included in the stiffness in all linear solution sequences that calculatea differential stiffness. The solution sequences are SOLs 103, 105, 107 to 112, 115and 116 (see also the parameter “FOLLOWK” ). In addition, follower force effectsare included in the force balance in the nonlinear static and nonlinear transient

144 CHBDYEGeometric Surface Element Definition (Element Form)

dynamic solution sequences, SOLs 106, 129, 153, and 159, if geometric nonlineareffects are turned on with PARAM,LGDISP,1. The follower force stiffness isincluded in the nonlinear static solution sequences (SOLs 106 and 153) but notin the nonlinear transient dynamic solution sequences (SOLs 129 and 159).


1. To apply a pressure load with constant magnitude (with respect to time), SID isselected by Case Control command LOAD = SID for both static and transientanalyses.

2. To apply a time-dependent pressure load, SID is referenced by the fieldEXCITEID = SID in the TLOAD1 entry. Time-dependent loads are selectedby Case Control command DLOAD.

3. In large deformation analysis, the direction of normal pressure loads (i.e.,CID, N1, N2 and N3 not specified) follows the deformation of the element bydefault. The use of LOADOPT = 0 in NXSTRAT entry causes pressure loads tobe independent of deformation, i.e., the direction of pressure loads maintainsits original direction.

4. CID, if specified, must be a rectangular coordinate system. Otherwise an errormessage will be issued.

Updated CHBDYE Bulk Entry

CHBDYE Geometric Surface Element Definition (Element Form)

Defines a boundary condition surface element with reference to a heat conductionelement.

Format:

1 2 3 4 5 6 7 8 9 10

CHBDYE EID EID2 SIDE IVIEWF IVIEWB RADMIDF RADMIDB

Example:

CHBDYE 2 10 1 3 3 2 2

CHBDYE 145Geometric Surface Element Definition (Element Form)

Fields:

Field Contents

EID Surface element identification number for a specific side of aparticular element. See Remarks 1 and 9. (Unique Integer > 0among all elements)

EID2 A heat conduction element identification number. (Integer > 0)

SIDE A consistent element side identification number. See Remark 6 . (1≤ Integer ≤ 6)

IVIEWF A VIEW entry identification number for the front face of the surfaceelement. (Integer > 0, see Remark 2 for the default.)

IVIEWB A VIEW entry identification number for the back face of the surfaceelement. (Integer > 0, see Remark 2 for the default.)

RADMIDF RADM identification number for the front face of surface element.(Integer ≥ 0, see Remark 2 for the default.)

RADMIDB RADM identification number for the back face of the surfaceelement. (Integer ≥ 0, see Remark 2 for the default.)

Remarks:

1. EID is a unique elemental ID associated with a particular surface element.EID2 identifies the general heat conduction element being considered for thissurface element.

2. The defaults for IVIEWF, IVIEWB, RADMIDF, and RADMIDB may be specifiedon the BDYOR entry. If a particular field is blank both on the CHBDYE entryand the BDYOR entry, then the default is zero.

3. For the front face of shell elements, the right-hand rule is used as one progressesaround the element surface from G1 to G2 to ... Gn. For the edges of shellelements or the ends of line elements, an outward normal is used to define thefront surface.

4. If the surface element is to be used in the calculation of view factors, it musthave an associated VIEW entry.

5. All conduction elements to which any boundary condition is to be applied mustbe individually identified with the application of one of the surface elemententries: CHBDYE, CHBDYG, or CHBDYP.


6. Side conventions for solid elements.

The sides of the solid elements are numbered consecutively according to theorder of the grid point numbers on the solid element entry. The sides of solidelements are either quadrilaterals or triangles. For each element type, tabulatethe grid points (gp) at the corners of each side.

Table 6-7. 8-node or 20-node CHEXA

side gp gp gp gp

1 4 3 2 1

2 1 2 6 5

3 2 3 7 6

4 3 4 8 7

5 4 1 5 8

6 5 6 7 8

Table 6-8. CPENTA

side gp gp gp gp

1 3 2 1

2 1 2 5 4

3 2 3 6 5

4 3 1 4 6

5 4 5 6

Table 6-9. CPYRAM

side gp gp gp gp

1 4 3 2 1

2 1 2 5

3 2 3 5

4 3 4 5

5 4 1 5

CHBDYE 147Geometric Surface Element Definition (Element Form)

Table 6-10. CTETRA

side gp gp gp

1 3 2 1

2 1 2 4

3 2 3 4

4 3 1 4

7. Side conventions for shell elements.

Side 1 of shell elements (top) are of an AREA type, and additional sides (2through a maximum of 5 for a QUAD) are of LINE type. (See “CHBDYG” forsurface type definition.)

Area Type Sides –The first side is that given by the right-hand rule on the shellelements grid points.

Line Type Sides –The second side (first line) proceeds from grid point 1 to gridpoint 2 of the shell element, and the remaining lines are numbered consecutively.The thickness of the line is that of the shell element, and the normal to the line isoutward from the shell element in the plane of the shell. Note that any midsidenodes are ignored in this specification.

8. Side conventions for line elements.

LINE elements have one linear side (side 1) with geometry that is the same asthat of the element and two POINT-type sides corresponding to the two pointsbounding the linear element (first grid point-side 2; second grid point-side 3).

The TUBE-type element has two linear sides of type TUBE. The first siderepresents the outside with diameters equal to that of the outside of the tube.The second side represents the inside with diameters equal to that of the insideof the tube.

Point Sides – Point sides may be used with any linear element. The directionof the outward normals of these points is in line with the element axis, butpointing away from the element. The area assigned to these POINT-type sides isconsistent with the element geometry.

Rev Sides – The axisymmetric elements CTRIAX6, CTRAX3, CTRAX6,CQUADX4, and CQUADX8 have rev sides associated with them. The positiveface identification normals point away from the element. The first side isdetermined by their grid point order:


Table 6-11. Axisymmetric rev sides

Element Number of rev sides First side

CTRIAX6 3 G1, G2, and G3

CTRAX3 3 G1 and G2

CTRAX6 3 G1, G4, and G2

CQUADX4 4 G1 and G2

CQUADX8 4 G1, G5, and G2

9. The EID field on all CHBDYi entries is entered as positive integer, but the EIDreferenced on certain load or boundary condition entries can be entered as a+EID or -EID to represent the front or back of the CHBDYi entry, respectively.For example, entering a -EID on a QVECT entry applies a heat flux opposite tothe CHBDYi normal orientation vector. The table below summarizes the thermalload and boundary conditions, if they support CHBDYi entires, and if so, if theysupport a negative EID.

Loads Description CHBDYiSupported

NegativeEIDSupported

QVECT Directional heat flux from a distantsource.

Yes Yes

QVOL Volumetric internal heat generation. No

QHBDY Heat flux applied to an area defined ongrid points. No

QBDY1 Heat flux applied to surface elements. Yes Yes

QBDY2 Heat flux applied to grid pointsassociated with a surface element.

Yes No

QBDY3 Heat flux applied to surface elementswith control node capability. Yes Yes

SLOAD Power into a grid or scalar point. No

NOLIN1 Nonlinear transient load as a tabularfunction.

No

NOLIN2 Nonlinear transient load as a product oftwo variables.

No

NOLIN3Nonlinear transient load as a positivevariable raised to a power. No

NOLIN4Nonlinear transient load as a negativevariable raised to a power. No

BoundaryConditions

GEOMCHECK 149Specifies Geometry Check Options

CONV CONV Free convection Yes No

CONVM CONVM Forced convection (fluid“element”)

Yes, butCHBDYPonly

No

RADBC Radiation exchange with space Yes Yes*RADSET Radiation exchange within an enclosure NoRADLST Listing of Enclosure Radiation Faces Yes Yes*

* RADBC and RADLST entries do support a negative EID, although the frontand back IVIEWi and RADMIDi fields already allow for this control, and anegative EID is typically not needed. IVIEWF and RADMIDF are associatedwith the CHBDYi normal orientation vector and IVIEWB and RADMIDB withthe opposite. For radiation problems, if the RADMIDF or RADMIDB is zero,default radiant properties assume perfect black body behavior.

Updated GEOMCHECK Executive Control Statement

GEOMCHECK Specifies Geometry Check Options

Specifies tolerance values for (optional) finite element geometry tests.

Format:

Describers:

Describer Meaning

test_keyword A keyword associated with the particular element geometrytest. See Remark 2 . for a list of acceptable selections.

tol_value Tolerance value to be used for the specified test. See Remark 2. for default values of the test tolerances.

n The maximum number of messages that will be produced. Thedefault is 100 messages for each element type. See Remark 3 .

FATAL Geometry tests that exceed tolerance values produce fatalmessages. See Remark 4 .

150 GEOMCHECKSpecifies Geometry Check Options

Describer Meaning

INFORM Geometry tests that exceed tolerance values produceinformative messages. See Remark 4 .

WARN Geometry tests that exceed tolerance values produce warningmessages. See Remark 4 .

SUMMARY A summary table of the geometry tests performed is produced.No individual element information messages are output.

NONE None of the optional element geometry tests will be performed.

Remarks:

1. The GEOMCHECK directive controls the number and severity of certaininformational and warning messages produced by element matrix generationgeometry checking operations. Controls are currently available for the CQUAD4,CQUADR, CTRIA3, CTRIAR, CHEXA, CPENTA, CPYRAM, CTETRA, CBAR,CBEAM, CTRAX3, CTRAX6, CQUADX4, and CQUADX8 elements only. MultipleGEOMCHECK directives may be present. Continuations are acceptable.

2. The following table and associated remarks summarize the acceptablespecifications for test_keyword. See the second table and associated remarks forCTRAX3, CTRAX6, CQUADX4, and CQUADX8 specifications.

Name Value Type Default CommentQ4_SKEW Real≥0.0 30.0 Skew angle in degreesQ4_TAPER Real≥0.0 0.50 Taper ratio

Q4_WARP Real≥0.0 0.05 Surface warping factorQ4_IAMIN Real≥0.0 30.0 Minimum Interior Angle in degreesQ4_IAMAX Real≥0.0 150.0 Maximum Interior Angle in degreesT3_SKEW Real≥0.0 10.0 Skew angle in degreesT3_IAMAX Real≥0.0 160.0 Maximum Interior Angle in degreesTET_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioTET_EPLR Real≥0.0 0.50 Edge point length ratioTET_DETJ Real 0.0 | J | minimum valueTET_DETG Real 0.0 | J | minimum value at vertex pointHEX_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioHEX_EPLR Real≥0.0 0.50 Edge point length ratioHEX_DETJ Real 0.0 | J | minimum value


Name Value Type Default CommentHEX_WARP Real≥0.0 0.707 Face warp coefficientPYR_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioPYR_EPLR Real≥0.0 0.50 Edge point length ratioPYR_DETJ Real 0.0 | J | minimum valuePYR_WARP Real≥0.0 0.707 Face warp coefficientPEN_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioPEN_EPLR Real≥0.0 0.50 Edge point length ratioPEN_DETJ Real 0.0 | J | minimum valuePEN_WARP Real≥0.0 0.707 Quadrilateral face warp coefficientBEAM_OFF Real≥0.0 0.15 CBEAM element offset length ratioBAR_OFF Real≥0.0 0.15 CBAR element offset length ratio

where:

• Test_keyword names starting with the characters Q4 are applicable toCQUAD4 and CQUADR elements. Test_keyword names starting withthe characters T3 are applicable to CTRIA3 and CTRIAR elements.Test_keyword names starting with the characters TET_ are applicable toCTETRA elements. Test_keyword names starting with the characters HEX_are applicable to CHEXA elements. Test_keyword names starting with thecharacters PYR_ are applicable to CPYRAM elements. Test_keyword namesstarting with the characters PEN_ are applicable to CPENTA elements.

• Skew angle for the quadrilateral element is defined to be the angle betweenthe lines that join midpoints of the opposite sides of the quadrilateral. Skewangle for the triangular element is defined to be the smallest angle at anyof the three vertices.

• Interior angles are defined to be the angles formed by the edges that meet atthe corner node of an element. There are four for quadrilateral shapes andthree for triangular shapes.

• Taper ratio for the quadrilateral element is defined to be the ratio of thearea of the triangle formed at each corner grid point to one half the area ofthe quadrilateral. The largest of the four ratios is compared against thetolerance value. It may be noted that as the ratio approaches 1.0, the shapeapproaches a triangle.

• Surface warping factor for a quadrilateral is defined to be the distance ofthe corner points of the element to the mean plane of the grid points dividedby the average of the element’s diagonal lengths. For flat elements (all ofthe grid points lie in a plane), this factor is zero.


• The edge point length ratio test is only performed for solid elements whenedge node points exist. The test evaluates the relative position of the edgenode point along a straight line connecting the two vertex nodes of thatedge. Ideally, the edge point should be located on this line at a point midwaybetween the two end points. The default tolerance allows the edge nodeto be positioned anywhere between the two quarter points on this line.In addition, the angles between the lines joining the edge node and theend points are determined. If the angle is greater than 30°, then the edgepoint length ratio test is considered violated and a diagnostic message willbe generated if appropriate.

• The face warp coefficient test tolerance is the cosine of the angle formedbetween the normal vectors located at diagonally opposite corner pointson each face surface. This value is 1.0 for a face where all 4 corners lie ina plane. The default tolerance allows angles of up to 45° before a messageis generated.

• The longest edge to shortest edge aspect ratio test evaluates the ratio of thelongest length to the shortest length encountered in the element. If the ratioexceeds the tolerance, an informational message is produced.

• For TET_AR, the shortest edge is computed by taking 6 times the volumeand dividing it by the largest height value. The largest height value is theminimum distance between a corner node and the opposite plane.

The following table and associated remarks summarize the acceptabletest_keyword specifications for elements CTRAX3, CTRAX6, CQUADX4, andCQUADX8.

Name Value Type Default CommentTRX_IAMN Real≥0.0 30.0 Minimum Interior Angle in degreesTRX_IAMX Real≥0.0 100.0 Maximum Interior Angle in degreesTRX_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioTRX_EPLR Real≥0.0 0.5 Edge point length ratioQDX_IAMN Real≥0.0 30.0 Minimum Interior Angle in degreesQDX_IAMX Real≥0.0 150.0 Maximum Interior Angle in degreesQDX_AR Real≥0.0 100.0 Longest edge to shortest edge aspect ratioQDX_SKEW Real≥0.0 30.0 Skew angle in degreesQDX_TAPR Real≥0.0 0.5 Taper ratio

QDX_EPLR Real≥0.0 0.5 Edge point length ratio

where:


• Test_keyword names starting with the characters QDX are applicable toCQUADX4 and CQUADX8 elements except QDX_EPLR only applies toCQUADX8. Test_keyword names starting with the characters TRX areapplicable to CTRAX3 and CTRAX6 elements except TRX_EPLR onlyapplies to CTRAX6.

• Skew angle for the quadrilateral elements is defined to be the angle betweenthe lines that join midpoints of the opposite sides of the quadrilateral.

• Interior (min and max) angles are defined to be the angles formed by theedges that meet at the corner node of an element. There are four forquadrilateral shapes and three for triangular shapes.

• Taper ratio for the quadrilateral elements is defined to be the ratio of thearea of the triangle formed at each corner grid point to one half of the areaof the quadrilateral. The largest of the four ratios is compared against thetolerance value. It may be noted that as the ratio approaches 1.0, the shapeapproaches a triangle.

• The edge point length ratio test is only performed for elements when edgenode points exist. The test evaluates the relative position of the edge nodepoint along a straight line connecting the two vertex nodes of that edge.Ideally, the edge point should be located on this line at a point midwaybetween the two end points. The default tolerance allows the edge node to bepositioned anywhere between the two quarter points on this line.

• The aspect ratio test evaluates the ratio of the longest length edge to theshortest edge encountered in the element.

3. A single line summarizing the results of all tests for an element will be output ifany of the geometry tests exceeds the test tolerance. Only the first n of thesemessages will be produced. A summary of the test results indicating the numberof tolerances exceeded as well as the element producing the worst violation isalso output. If the SUMMARY keyword has been specified, only the summarytable is produced and none of the single line element messages will be output.

Solutions which fail with numerical problems, i.e. negative jacobian, reportdifferently based on the sign of MSGLIMIT. When troubleshooting a failedanalysis, you may find it useful to switch between the following two strategies:

Value ofMSGLIMIT

Meaning when numerical fatal errors occur


> 0 (positive)

If numerical problems are found, a FATAL ERROR messageis generated without the offending element ID, the analysisterminates, but the GEOMCHECK criteria is processed andoutput for all elements.

This strategy works when only a few elements fail theGEOMCHECK. However, if there are hundreds or thousands offailures, diagnosing the critical elements could become difficult.In addition, the offending element ID may or may not havefailed the GEOMCHECK criteria depending on the criteria youentered.

< 0 (negative)

If numerical problems are found, a FATAL ERROR messageis generated which includes the offending element ID, theanalysis terminates, yet GEOMCHECK is not processed for allelements. The downside of using a negative MSGLIMIT is ifthe model contains multiple offending elements, the procedureof fixing/rerunning needs to be repeated until all offendingelements have been corrected.

4. When SUMMARY is not specified, each geometry test that exceeds the tolerancewill be identified in the single line output summary by an indicator based on thespecification for MSGTYPE. For the FATAL option, the indicator is “FAIL”; forthe INFORM option, it is “xxxx”; for the WARN option, it is “WARN”. If theFATAL option is specified and any test fails, the run is terminated.

5. There are two categories of element checks in an NX Nastran solution:

• The system controlled checks will always occur whether GEOMCHECK isdefined or not. As the name implies, there is no user control to these checks.The system controlled checks will always produce a fatal error if an elementis found which prevents the formulation of the finite element matrix.

• GEOMCHECK is the optional, user controlled check, and can optionallygenerate a fatal error if it finds an element which fails the user definedcriteria. By default, GEOMCHECK does not produce fatal errors.

The system controlled and user controlled checks are similar for elementslike shells, but different for elements like solids. Be aware that whenMSGTYPE=inform, GEOMCHECK may flag a poor quality element with aninformational message, the element may pass the system check, and the solvemay complete. MSGTYPE should be set appropriately if you expect fatal errorsin these cases.

Fatal errors can also be forced by assigning a negative value to MSGLIMIT, forexample, MSGLIMIT=-100. This is also useful since a specific “FAIL” messagewill be reported for each element failing the GEOMCHECK criteria.


Examples:

1. Set the tolerance for the CQUAD4 element skew angle test to 15.0 degrees andlimit messages to 50.

GEOMCHECK Q4_SKEW=15.0,MSGLIMIT=50

2. Limit messages to 500 for each element type.

GEOMCHECK MSGLIMIT=500

3. Set the message type to fatal for CQUAD4 element taper tests.

GEOMCHECK Q4_TAPER,MSGTYPE=FATAL

4. Request summary table output only using default tolerance values.

GEOMCHECK SUMMARY

CPYRAM Element Stress/Strain Item CodesReal Stresses or Strains Complex Stresses or StrainsElement Name

(Code)Item Code Item Item Code Item Real/Mag. or

Imag./ Phase

2 Stress/Straincoordinatesystem

2 Stress coordinatesystem

3 Coordinate type(Character)

3 Coordinate type(Character)

4 Number of activepoints

4 Number of activepoints

5 External grid ID 5 External grid ID

(0=center) (0=center)

6 Normal x 6 Normal x RM

7 Shear xy 7 Normal y RM

8 First principal 8 Normal z RM

9 First principal xcosine

9 Shear xy RM

10 Second principalx cosine

10 Shear yz RM

11 Third principal xcosine

11 Shear zx RM

12 Mean pressure 12 Normal x IP

13 von Mises oroctahedral shearstress

13 Normal y IP

CPYRAM

(255)

Linear


Real Stresses or Strains Complex Stresses or StrainsElement Name(Code)

Item Code Item Item Code Item Real/Mag. orImag./ Phase

14 Normal y 14 Normal z IP

15 Shear yz 15 Shear xy IP

16 Second principal 16 Shear yz IP

17 First principal ycosine

17 Shear zx IP

18 Second principaly cosine

18-82 Repeat items 5through 17 forfive corners

19 Third principal ycosine

20 Normal z

21 Shear zx

22 Third principal

23 First principal zcosine

24 Second principalz cosine

25 Third principal zcosine

26-130 Repeat items 5through 25 forfive corners




3 0 (Result at Center)

4 Stress in X

5 Stress in Y

6 Stress in Z

7 Stress in XY

8 Stress in YZ

9 Stress in ZX

10 Equivalent stress

11 Equivalent plasticstrain

12 Effective creep strain

13 Strain in X

14 Strain in Y

15 Strain in Z

16 Strain in XY

17 Strain in YZ

18 Strain in ZX

19 Grid 1 ID

20–34 Same as items 4–18 forcorner 1

35 Grid 2 ID


51 Grid 3 ID


67 Grid 4 ID


83 Grid 5 ID

CPYRAM

(256)

Nonlinear


Not applicable




2 Grid

3 Grid ID

4 Stress in X

5 Stress in Y

6 Stress in Z

7 Stress in XY

8 Stress in YZ

9 Stress in ZX

10 Pressure

11 Volumetric strain

12 Strain in X

13 Strain in Y

14 Strain in Z

15 Strain in XY

16 Strain in YZ

17 Strain in ZX

CPYRAMFD

(257) LinearPyramid

(258) ParabolicPyramid

NonlinearHyperelastic

18-77 Repeat items 3through 17 for 5grid points

Not applicable

CROD and CBAR Enhancements 159

6.2 CROD and CBAR Enhancements

Torsional Mass Moment of Inertia

The CROD and CBAR elements previously did not include the torsional massmoment of inertia in the mass matrix, while the CBEAM did, which led todifferences when comparing results of an equivalent model.

Now the torsional mass moment of inertia can be optionally included on the CRODand CBAR mass matrices. By default, the torsional mass is not calculated for theCROD or CBAR.

The new parameter TORSIN can be used to turn on/off the option:

PARAM,TORSIN

0 – no torsional mass moment of inertia for CROD and CBAR (default)

1 – include torsional mass moment of inertia for CROD and CBAR

2 – include torsional mass moment of inertia for CBAR

3 – include torsional mass for CROD

The CBAR axial torsional mass moment of inertia is calculated similar to theCBEAM element using the equation:

Ixx = rL(I1 + I2)

where:

Ixx = torsional mass moment of inertia

r = density

L = length of element

I1 and I2 = area moments of inertia

The CROD axial torsional mass moment of inertia is calculated using the equation:

Ixx = rLIx

where:

Ix = J = torsional constant

160 CROD and CBAR Enhancements

Lumped Mass Approach

In previous releases the lumped mass calculation method for CROD and CBARelements was different than the CBEAM, which led to differences when comparingresults of an equivalent model.

Now the default lumped mass calculation for the CROD and CBAR has beenupdated to use the same method as the CBEAM. For compatibility with earlierversions, the new system cell 474 lets you revert back to the original lumped massmethod for the CBAR, CROD, or both CBAR and CROD. By default, the newlumped mass calculation is used for both the CROD and CBAR elements.

System cell 474 has the following options:

0 – the new lumped mass calculation is used for the CROD and CBAR elements(default)

1 – old CBAR lumped mass method

2 – old CROD lumped mass method

3 – old CBAR and CROD lumped mass methods

New Axisymmetric Elements Supported SOL 200 161

6.3 New Axisymmetric Elements Supported SOL 200The four new axisymmetric elements CTRAX3, CTRAX6, CQUADX4, andCQUADX8 introduced in NX Nastran 6.0 create an axisymmetric category whichsupports all capabilities of the original elements (CTRIAX, CQUADX, CTRIAX6)yet is consistent across solutions. The new elements are supported in solutions101, 103, 105, 107, 108, 109, 111, 112, 129, 153, 159. Now design sensitivity andoptimization (solution 200) has been added as a supported solution.

The following summarizes the supported inputs when using the CTRAX3,CTRAX6, CQUADX4, and CQUADX8 with solution 200.

• Case Control Commands:

Supported: DESOBJ, DESSUB.

Not supported: DESGLB.

• Bulk Entries:

Supported: DESVAR, DVCREL1, DVMREL1, DRESP1, DOPTPRM,DSCREEN, DCONSTR, DVGRID, BNDGRID.

Not supported: DVCREL2, DVMREL2, DVPREL1, DVPREL2, DRESP2,DRESP3, DEQATN, DVBSHAP, DVSHAP.

• DRESP1 Response Types (RTYPE field):

Supported: WEIGHT, VOLUME, EIGN, DISP, STRESS, STRAIN.

Not supported: All other response types on DRESP1 not listed above.

Axisymmetric Element Optimization Example:

162 New Axisymmetric Elements Supported SOL 200

Description:

• CQUADX4 axisymmetric elements model a 3D ring with a pressure load onthe inside face.

• The objective is to minimize the weight. More specifically, the DESOBJ casecontrol command selects the DRESP1 response for the objective.

DESOBJ(MIN) = 12....DRESP1 12 W WEIGHT

• The design constraint is the radial component of stress for element 23, with alower bound of –250 and upper bound of –225. More specifically, the DESSUBcase control command selects the DCONSTR and DRESP1 bulk entries. TheDRESP1 response uses the stress item code 4 (ATTA field) indicating theradial stress component (see CQUADX4 item codes in the Quick ReferenceGuide), and element id 23 (ATTI field). The DCONSTR bounds the radialstress component between –250 to –225.

DESSUB = 1...DCONSTR 1 1 -250.0 -225.0DRESP1 1 SIG STRESS ELEM 4 23

• Finally, a design variable allows grids 43, 45, 47, and 49 to move radiallywithin the bounds of 17.5 to 22.5. These grids are modeled initially 20mmfrom the origin.

DESVAR 1 DV43 20. 17.5 22.5DESVAR 2 DV45 20. 17.5 22.5DESVAR 3 DV47 20. 17.5 22.5

New Axisymmetric Elements Supported SOL 200 163

DESVAR 4 DV49 20. 17.5 22.5....DVGRID 1 43 1. 1. 0. 0.DVGRID 2 45 1. 1. 0. 0.DVGRID 3 47 1. 1. 0. 0.DVGRID 4 49 1. 1. 0. 0.$

Example input file:

$ DESCRIPTION - Optimization with Axisymmetric Element$ Element type: CQUADX4$ Optimization for Static Analysis$$ SOLUTION - 200$$ OUTPUT - DISP & STRESS$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*SOL 200CEND$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$* CASE CONTROL$$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*ECHO = NONEOUTPUTDISPLACEMENT = ALLSTRESS = ALLSUBCASE 1DESOBJ(MIN) = 12DESSUB = 1ANALYSIS = STATICSSPC = 1LOAD = 1$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*$* BULK DATA$*$*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*BEGIN BULK$*$*PARAM AUTOSPC YESPARAM POST -2PARAM,PRGPST,NO$*$*GRID 1 10.0 0.0 0.0GRID 3 10.0 0.0 3.333333GRID 5 10.0 0.0 6.666667GRID 7 10.0 0.0 10.0

164 New Axisymmetric Elements Supported SOL 200

GRID 15 13.333330.0 0.0GRID 17 13.333330.0 3.333333GRID 19 13.333330.0 6.666667GRID 21 13.333330.0 10.0GRID 29 16.666670.0 0.0GRID 31 16.666670.0 3.333333GRID 33 16.666670.0 6.666667GRID 35 16.666670.0 10.0GRID 43 20.0 0.0 0.0GRID 45 20.0 0.0 3.333333GRID 47 20.0 0.0 6.666667GRID 49 20.0 0.0 10.0CQUADX4 20 2 15 17 31 29CQUADX4 23 2 17 19 33 31CQUADX4 24 2 31 33 47 45CQUADX4 25 2 5 7 21 19CQUADX4 26 2 19 21 35 33CQUADX4 27 2 33 35 49 47CQUADX4 19 2 1 3 17 15CQUADX4 21 2 29 31 45 43CQUADX4 22 2 3 5 19 17MAT1 1 22400.0 .3 8.17-3 1.35-5 20.0 ++ 0.0 0.0 0.0PSOLID 2 1 0$$SPC1 1 123456 1 3 5 7$SPC,1,1,3,0.0$$PLOADX1 1 19 990.0 990.0 1 3 0.0PLOADX1 1 22 990.0 990.0 3 5 0.0PLOADX1 1 25 990.0 990.0 5 7 0.0$DCONSTR 1 1 -250.0 -225.0$$234567812345678123456781234567812345678123456781234567812345678DESVAR 1 DV43 20. 17.5 22.5DESVAR 2 DV45 20. 17.5 22.5DESVAR 3 DV47 20. 17.5 22.5DESVAR 4 DV49 20. 17.5 22.5$DRESP1 12 W WEIGHTDRESP1 1 SIG STRESS ELEM 4 23$$234567812345678123456781234567812345678123456781234567812345678DVGRID 1 43 1. 1. 0. 0.DVGRID 2 45 1. 1. 0. 0.DVGRID 3 47 1. 1. 0. 0.DVGRID 4 49 1. 1. 0. 0.$ENDDATA

Damping Enhancements 165Generalized Spring-and-Damper Property

6.4 Damping Enhancements

PBUSH & PBUSHT Structural Damping

The previous PBUSH bulk entry only supported a single structural damping value(GE1) which applied to all six degrees-of-freedom. Now the PBUSH bulk entrysupports a value in each degree-of-freedom (GE1, GE2, GE3, GE4, GE5, GE6).

Similarly, the previous PBUSHT bulk entry only supported a single tabulatedfrequency dependent structural damping (TGEID1), which applied to all 6degrees-of-freedom. Now the PBUSHT bulk entry supports tabulated frequencydependent structural damping for each degree-of-freedom (TGEID1, TGEID2,TGEID3, TGEID4, TGEID5, TGEID6).

If any PBUSH or PBUSHT bulk entries have any of the fields GE2-GE6 andTGEID2-TGEID6 defined, then all PBUSH and PBUSHT bulk entries are assumedto have all GE1-GE6 and TGEID1-TGEID6 fields defined. Therefore, when youuse any of the GE2-GE6 and/or TGEID2-TGEID6 fields, it is important to fullydefine all degrees-of-freedom deemed critical to the result, since a blank field willdefault to a zero value.

You can use the new parameter BSHDAMP to optionally ignore any of theGE2-GE6 and TGEID2-TGEID6 fields, and only use GE1 and TGEID1. By default,the new fields are considered.

PARAM,BSHDAMP

= SAME The PBUSH/PBUSHT bulk entry fields GE2-GE6/TGEID2-TGEID6 areignored, and only fields GE1/TGEID1 are considered.

= DIFF (default) The PBUSH/PBUSHT bulk entry fieldsGE2-GE6/TGEID2-TGEID6 are used. If any of the fields GE2-GE6and TGEID2-TGEID6 are defined, then all PBUSH and PBUSHT bulk entriesare assumed to have all GE1-GE6 and TGEID1-TGEID6 fields defined, and anyblank fields are considered a zero value.

Updated PBUSH and PBUSHT Bulk Entries

PBUSH Generalized Spring-and-Damper Property

Defines the nominal property values for a generalized spring-and-damperstructural element.

Format:

1 2 3 4 5 6 7 8 9 10PBUSH PID “K” K1 K2 K3 K4 K5 K6

166 PBUSHGeneralized Spring-and-Damper Property

1 2 3 4 5 6 7 8 9 10

“B” B1 B2 B3 B4 B5 B6

“GE” GE1 GE2 GE3 GE4 GE5 GE6

“RCV” SA ST EA ET

Example 1: Stiffness and structural damping are specified.

PBUSH 35 K 4.35 2.4 3.1

GE .06

RCV 7.3 3.3

Example 2: Damping force per unit velocity is specified.

PBUSH 35 B 2.3

Example 3: All damping types are specified.

PBUSH 2 K 1000.0 1000.0

B 0.02 0.02

GE 0.01 0.02

RCV 1.0 1.0

Fields:

Field Contents

PID Property identification number. (Integer > 0)

“K” Flag indicating that the next 1 to 6 fields are stiffness values in theelement coordinate system. (Character)

Ki Nominal stiffness values in directions 1 through 6. See Remarks 2 and3. . (Real; Default = 0.0)

“B” Flag indicating that the next 1 to 6 fields are force-per-velocitydamping. (Character)

Bi Nominal damping coefficient in units of force per unit velocity. SeeRemark 3 . (Real; Default = 0.0)

“GE” Flag indicating that the next fields, 1–6, are structural dampingconstants. See Remark 7 . (Character)

PBUSH 167Generalized Spring-and-Damper Property

Field Contents

GEi Nominal structural damping constant in directions 1–6. See 2 and 3.(Real; Default = 0.0)

“RCV” Flag indicating that the next 1 to 4 fields are stress or straincoefficients. (Character)

SA Stress recovery coefficient in the translational component numbers 1through 3. (Real; Default = 1.0)

ST Stress recovery coefficient in the rotational component numbers 4through 6. (Real; Default = 1.0)

EA Strain recovery coefficient in the translational component numbers 1through 3. (Real; Default = 1.0)

ET Strain recovery coefficient in the rotational component numbers 4through 6. (Real; Default = 1.0)

Remarks:

1. Ki, Bi, or GEi may be made frequency dependent for both direct and modalfrequency response by use of the PBUSHT entry.

2. The nominal values are used for all analysis types except frequency response. Formodal frequency response, the normal modes are computed using the nominal Kivalues. The frequency-dependent values are used at every excitation frequency.

3. If PARAM,W4 is not specified, GEi is ignored in transient analysis.

4. The element stresses are computed by multiplying the stress coefficients withthe recovered element forces.

5. The element strains are computed by multiplying the strain coefficients withthe recovered element displacements.

6. The “K”, “B”, “GE”, or “RCV” entries may be specified in any order.

7. To obtain the damping coefficient GE, multiply the critical damping ratio C/Coby 2.0.

8. Applicable fields refer to directions in the element’s coordinate system.

9. For upward computability, if ONLY GE1 is specified on ALL PBUSH entries andGEi, i=2 – 6 are blank on ALL PBUSH entries, then a single structural dampingfor each PBUSH applied to all defined Ki for each PBUSH is assumed. If ANY

168 PBUSHTFrequency Dependent or Nonlinear Force Deflection Spring and Damper Property

PBUSH entry has a GEi, i=2 – 6 specified, then the GEi fields are consideredvariable on ALL PBUSH entries.

PBUSHT Frequency Dependent or Nonlinear Force Deflection Spring andDamper Property

Defines the frequency dependent properties or the stress dependent properties fora generalized spring and damper structural element.

Format:

1 2 3 4 5 6 7 8 9 10PBUSHT PID “K” TKID1 TKID2 TKID3 TKID4 TKID5 TKID6

“B” TBID1 TBID2 TBID3 TBID4 TBID5 TBID6

“GE” TGEID1 TGEID2 TGEID3 TGEID4 TGEID5 TGEID6

“KN” TKNID1 TKIND2 TKNID3 TKIND4 TKIND5 TKIND6

Example:

PBUSHT 2 K 100 101

B 102 103

GE 104 105

Fields:

Field Contents

PID Property identification number that matches the identificationnumber on a PBUSH entry. (Integer > 0)

“K” Flag indicating that the next 1 to 6 fields are stiffness frequencytable identification numbers. (Character)

TKIDi Identification number of a TABLEDi entry that defines the stiffnessvs. frequency relationship. (Integer ≥ 0; Default = 0)

“B” Flag indicating that the next 1 to 6 fields are force per velocityfrequency table identification numbers. (Character)

TBIDi Identification number of a TABLEDi entry that defines the forceper unit velocity damping vs. frequency relationship. (Integer ≥0; Default = 0)

PBUSHT 169Frequency Dependent or Nonlinear Force Deflection Spring and Damper Property

Field Contents

“GE” Flag indicating that the next fields 1–6 are structural dampingfrequency table identification numbers. (Character)

TGEIDi Identification number of a TABLEDi entry that defines thenon-dimensional structural damping vs. frequency relationship.(Integer ≥ 0; Default = 0)

“KN” Flag indicating that the next 1 to 6 entries are nonlinearforce-deflection table identification numbers. (Character)

TKNIDi Identification number of a TABLEDi entry that defines the force vs.deflection relationship. (Integer ≥ 0; Default = 0)

Remarks:

1. The “K”, “B”, and “GE” entries are associated with same entries on the PBUSHentry.

2. PBUSHT may only be referenced by CBUSH elements in the residual structurewhich do not attach to any omitted degrees-of-freedom.

3. The nominal values are used for all analysis types except frequencyresponse and nonlinear analyses. For frequency dependent modal frequencyresponse the system modes are computed using the nominal Ki values. Thefrequency-dependent values are used at every excitation frequency.

4. The “K”, “B”, “GE” or “KN” entries may be specified in any order.

5. The PBUSHT entry is ignored in all solution sequences except frequencyresponse or nonlinear analyses.

6. For nonlinear analysis, only the “KN” field is used.

7. For frequency responses, only the “K”, “B” and/or “GE” fields are used.

8. For upward computability, if ONLY TGEID1 is specified on ALL PBUSHTentries and TGEIDi, i=2 – 6 are blank on ALL PBUSHT entries, then a singlestructural damping table for each PBUSHT applied to all defined Ki for eachPBUSH is assumed. If ANY PBUSH entry has a TGEIDi, i=2 – 6 specified,then the GEi fields on the PBUSH and the TGEIDi fields on the PBUSHT areconsidered variable on ALL PBUSH and PBUSHT entries.

170 Nonstructural Mass Enhancements

PSHELL Structural Damping

The PSHELL bulk entry now supports the structural damping coefficient (GE)included on the associated materials

MID1 = membrane material

MID2 = bending material

MID3 = transverse shear

MID4 = membrane-bending coupling.

Previously, the structural damping coefficient included on the MID1 materialwas used for all MIDi.

The new parameter SHLDAMP has been created to turn on/off the capability.

PARAM,SHLDAMP

= SAME (default) The structural damping coefficient (GE) defined on a PSHELLMID1 material will be used by all MIDi for that PSHELL

= DIFF The structural damping coefficient (GE) defined on each PSHELL MIDiwill be used. When each PSHELL MIDi is used as described, any structuraldamping coefficient (GE) values which are blank default to zero.

6.5 Nonstructural Mass EnhancementsYou can define a nonstructural mass (NSM) on the PSHELL, PCOMP, PBAR,PBARL, PBEAM, PBEAML, PBCOMP, PROD, CONROD, PBEND, PSHEAR,PTUBE, PCONEAX, and PRAC2D property entries. The nonstructural mass isadded to the element structural mass to calculate the total mass of the element.

When you need to modify the mass of a few or many elements, the NSM input onthe property entries can be limiting. New nonstructural mass bulk entries havebeen created in NX Nastran 6.1 which allows more flexibility.

The new NSM and NSM1 bulk entries allow you to add nonstructural mass byproperty and/or element ID. Both have the TYPE field which points to either aproperty type, PSHELL for example, or ELEMENT, which indicates element IDswill be entered.

NSM has the form

Type, Mass Value, Id, Mass Value,ID...,

and NSM1 has the form

Type, Mass Value, ID, ID, ID, ...,

NSM 171

Since each NSM and NSM1 has a single "TYPE", you can create multiple NSMand/or NSM1 entries, then combine them with the new NSMADD bulk entry toadjust the nonstructural mass across various property types and/or elements.

New NSM Case Control Command

NSM Nonstructural Mass

Selects Nonstructural Mass (NSM) set for mass generation.

Format:

NSM=n

Examples:

NSM=5

Describers:

Describer Meaning

n Set identification number of a nonstructural mass that appearson a NSM, NSM1, or NSMADD bulk data entry. (Integer > 0)

Remarks:

1. Different NSM sets may be selected for superelements and residual; but within asuperelement or residual it may not change within the subcase structure.

New NSM, NSM1, and NSMADD Bulk Entries

NSM

Defines a set of non structural mass by ID.

Format:

1 2 3 4 5 6 7 8 9 10

NSM SID TYPE ID VALUE ID VALUE ID VALUE

Example:

NSM 3 PSHELL 15 0.22

172 NSM1

Fields:

Field Contents

SID Nonstructural mass set identification number. (Integer > 0)

TYPE Set points to either property entries or element entries. Propertiesare: PSHELL, PCOMP, PBAR, PBARL, PBEAM, PBEAML,PBCOMP, PROD, CONROD, PBEND, PSHEAR, PTUBE,PCONEAX, and PRAC2D. ELEMENT list of individual element IDsof element that can have NSM. (Character)

ID Property or Element ID. (Integer > 0)

VALUE NSM value. (Real)

Remarks:

1. Non structural mass sets must be selected with Case Control command NSM =SID.

2. For CCONEAX, the element ID is 1000*ID+i, where i = 1 to harmonics numberplus one.

3. The ELSUM Case Control command will give a summary of both structural andnonstructural mass by element or property type.

NSM1

Alternate form for NSM entry. Defines non structural mass entries by VALUE,ID list.

Format:

1 2 3 4 5 6 7 8 9 10

NSM1 SID TYPE VALUE ID ID ID ID ID

ID ID ID etc.

Example:

NSM1 3 ELEMENT 0.44 1240 1500

NSM1 173

Alternate forms:

NSM1 SID TYPE VALUE ID THRU ID

NSM1 SID TYPE VALUE ALL

NSM1 SID TYPE VALUE ID THRU ID BY N

Fields:

Field Contents


TYPE Set points to either Property entries or Element entries. Propertiesare: PSHELL, PCOMP, PBAR, PBARL, PBEAM, PBEAML,PBCOMP, PROD, CONROD, PBEND, PSHEAR, PTUBE,PCONEAX, and PRAC2D. ELEMENT list of individual element IDsof element that can have NSM. (Character)

ID Property or Element ID. (Integer > 0 or “ALL” or “THRU” or “BY”or N (the BY increment))

VALUE NSM value. (Real)

Remarks:

1. Non structural mass sets must be selected with Case Control command NSM =SID.

2. For CCONEAX the element ID is 1000*ID+i , where i = 1 to harmonics numberplus one.

3. PBEAML and PBCOMP are treated as PBEAM, PBARL is treated asPBAR, and PCOMP is treated as PSHELL; therefore a command such as:NSM1,12,PCOMP,0.045,ALL would for example get all PSHELLs in the deck.The converted PCOMPs plus any existing PSHELLS would have .045 addedto their nonstructural mass.


174 NSMADD

NSMADD

Non structural mass set combination. Defines non structural mass as the sumof the sets listed.

Format:

1 2 3 4 5 6 7 8 9 10

NSMADD SID S1 S2 S3 S4 S5 S6 S7

S8 S9 S10 etc.

Example:

NSMADD 3 17 18 19 20

Fields:

Field Contents


Si Identification numbers of non structural mass sets defined via NSMand NSM1 entries. (Integer > 0)

Remarks:

1. The nonstructural mass sets must be selected with the Case Control commandNSM = SID.

2. No Si may be the identification number of a non structural mass set definedby another NSMADD entry.

3. NSMADD entries take precedence over NSM or NSM1 entries. If both have thesame set ID, only the NSMADD entry will be used.


CWELD/CFAST Improvement 175Weld or Fastener Element Connection

6.6 CWELD/CFAST ImprovementIn NX Nastran 6, two new CWELD formats were created: “ELPAT” and“PARTPAT”, which increased the area of a shell element patch by also includingthe connecting shell elements in the patch. In addition, the CFAST element wascreated, which is similar to the CWELD element, except that the CFAST stiffnessis entered directly on the element definition on the associated PFAST bulk dataentry. The CWELD stiffness is defined with a weld of given diameter.

It was previously required that the displacement coordinate system for all gridsconnected to a CWELD or CFAST patch must be the basic system (default). Thislimitation has been removed in NXN6.1, and any coordinate system can be used.

The remark on both the CWELD and CFAST which stated this limitation has beenremoved. The updated CWELD and CFAST bulk entries are included below.

CWELD Weld or Fastener Element Connection

Defines a weld or fastener connecting two surface patches or points.

ELPAT Format: (See Remark 2)

1 2 3 4 5 6 7 8 9 10

CWELD EWID PWID GS “ELPAT” GA GB

SHIDA SHIDB

XS YS ZS

ELPAT Example:

CWELD 7 29 233 ELPAT

15 28

PARTPAT Format: (See Remark 3)

1 2 3 4 5 6 7 8 9 10

CWELD EWID PWID GS “PARTPAT” GA GB

PIDA PIDB

XS YS ZS

PARTPAT Example:

CWELD 8 30 133 PARTPAT

101 201

176 CWELDWeld or Fastener Element Connection

GRIDID Format: (See Remark 4)

1 2 3 4 5 6 7 8 9 10

CWELD EWID PWID GS “GRIDID” GA GB SPTYP

GA1 GA2 GA3 GA4 GA5 GA6 GA7 GA8

GB1 GB2 GB3 GB4 GB5 GB6 GB7 GB8

XS YS ZS

GRIDID Example:

CWELD 7 29 233 GRIDID QT

15 28 31 35 46 51 55 60

3 5 8

ELEMID Format: (See Remark 5)

CWELD EWID PWID GS “ELEMID”

SHIDA SHIDB

XS YS ZS

ELEMID Example:

CWELD 3 28 354 ELEMID

15 16

ALIGN Format: (See Remark 6)

CWELD EWID PWID “ALIGN” GA GB

ALIGN Example:

CWELD 7 29 ALIGN 103 259

Fields:

Field Contents

EWID CWELD element identification number. See Remark 7 . (Integer > 0)

PWID Property identification number of a PWELD entry. (Integer > 0)

“ELPAT” Designates the input format as “ELPAT”. See Remark 2 . (Character;No default)

CWELD 177Weld or Fastener Element Connection

Field Contents

“PARTPAT” Designates the input format as “PARTPAT”. See Remark 3 .(Character; No default)

“GRIDID” Designates the input format as “GRIDID”. See Remark 4 .(Character; No default)

“ELEMID” Designates the input format as “ELEMID”. See Remark 5 .(Character; No default)

“ALIGN” Designates the input format as “ALIGN”. See Remark 6 . (Character;No default)

GA, GB Grid identification numbers used to define the location of theconnector on surface patch A and surface patch B, respectively whenformat is “ELPAT”, “PARTPAT”, “ELEMID”, or GRIDID. Whenformat is “ALIGN”, GA and GB are required, and they must be vertexnodes of shell elements. See Remark 1 . (Integer > 0 or blank)

GS Grid point identification number used to define the end locationsof the connector when GA/GB are undefined. The specific meaningof GS depends on whether it is used to define a location on a shellelement patch when format is “ELPAT” , “PARTPAT”, “ELEMID”,or “GRIDID”, or is used to define a point location when the formatis “ELEMID”, or “GRIDID”. See Remarks 1–6 for format specificdefinitions of GS. (Integer > 0)

XS,YS,ZS Defines the location of the connector on a shell element patch whenformat is “ELPAT” , “PARTPAT”, “ELEMID”, or “GRIDID”, and whenGA,/GB and GS are all undefined. See Remark 1. (Integer > 0)

PIDA The physical property identification number of a PSHELL bulk dataentry used to define surface patch A when format is “PARTPAT”.(Integer > 0)

PIDB The physical property identification number of a PSHELL bulk dataentry used to define surface patch B when format is “PARTPAT”.(Integer > 0)

SHIDA The shell element identification number used to define surface patchA when format is “ELPAT” or “ELEMID”. (Integer > 0)

SHIDB The shell element identification number used to define surface patchB when format is “ELPAT” or “ELEMID”.(Integer > 0)


Field Contents

SPTYP String indicating the type of surface patches A and B when formatis “GRIDID”. SPTYP=”QQ”, “TT”, “QT”, “TQ”, “Q” or “T”. Indicatesquadrilateral (“Q”) or triangular (“T”) surface patch. See Remark4 . (Character)

GAi Grid identification numbers defining surface patch A when format is“GRIDID”. GA1 to GA3 are required. See Remark 4 . (Integer > 0)

GBi Grid identification numbers defining surface patch B when formatis “GRIDID”. See Remark 4 . (Integer > 0)

Remarks:

1. GA/GB, or GS, or XS/YS/ZS, in that order of precedence, determine the location(s)of the CWELD connection on surface patches A and/or B, when format is“ELPAT”, “PARTPAT”, “ELEMID”, or “GRIDID”. The connection location onpatch A is a specification of grid point GA, or a projection of GS or XS/YS/ZSnormal to surface patch A. The location on patch B is a specification of grid pointGB, or a projection of GS or XS/YS/ZS normal to surface patch B. When GS orXS/YS/ZS are used, a normal projection must exist in order to define a validconnection element. GS or XS/YS/ZS do not need to lie on either surface patch Aor B. If GS or XS/YS/ZS are used to define the connection location, grid pointsare internally created at the connection location with an id, starting with thevalue specified on PARAM, OSWPPT.

2. If the “ELPAT” format is used, the shell element specified on the SHIDA alongwith those connected, and the shell element specified on the SHIDB along withthose connected, will create shell element patches A and B, respectively. Shellelement patches A and B are connected together with a weld of diameter D (Dis specified on the PWELD bulk data entry). The weld connection location onpatches A and B is determined as described in remark 1. Virtual grid points arecreated along the weld projected perimeter to connect all elements in a patch toeach other, and to the weld using constraint conditions.

3. If the “PARTPAT” format is used, the shell elements with a common propertyid specified on the new PIDA field, along with the connection location (definedbelow), determine the shell element for the center of patch A. This center shellelement, along with those connected are used to create shell element patch A.Patch B is created similarly, except PIDB is used (PIDA and PIDB must beunique). Patch A and B are connected together with a weld of diameter D (Dis specified on the PWELD bulk data entry). The weld connection location onpatches A and B is determined as described in remark 1. Virtual grid points are


created along the weld projected perimeter to connect all elements in a patch toeach other, and to the weld using constraint conditions.

4. The format “GRIDID” defines either a point to patch or a patch to patchconnection. For the point to patch connection, you must define GS and GAi. Thenit is assumed that GS is a shell vertex grid and GAi are grids describing a surfacepatch. For the patch to patch connection, you must define GS, GAi and GBi.Then GAi describes the first surface patch and GBi the second surface patch.

GAi are required for the “GRIDID” format. At least 3 and at most 8 grid IDsmay be specified for GAi and GBi, respectively. Triangular and quadrilateralelement definition sequences apply for the order of GAi and GBi, see Figure 6-2.Missing midside nodes are allowed.

Figure 6-2. Quadrilateral and Triangular Surface Patches Defined withFormat GRIDID

SPTYP defines the type of surface patches to be connected. SPTYP is required forthe “GRIDID” format to identify quadrilateral or triangular patches. Allowablecombinations are:

SPTYP Description

QQ Connects a quadrilateral surface patch A (Q4 to Q8) with aquadrilateral surface patch B (Q4 to Q8).

QT Connects a quadrilateral surface patch A (Q4 to Q8) with atriangular surface patch B (T3 to T6).

TT Connects a triangular surface patch A (T3 to T6) with a triangularsurface patch B (T3 to T6).

TQ Connects a triangular surface patch A (T3 to T6) with aquadrilateral surface patch B (Q4 to Q8).


SPTYP Description

Q Connects the shell vertex grid GS with a quadrilateral surfacepatch A (Q4 to Q8) if surface patch B is not specified

T Connects the shell vertex grid GS with a triangular surface patchA (T3 to T6) if surface patch B is not specified

5. The “ELEMID” format defines a point to patch connection, GS to SHIDA or apatch to patch connection, SHIDA to SHIDB.

6. The “ALIGN” format defines a point to point connection. GA and GB arerequired, and they must be vertex nodes of shell elements. GA and GB are notrequired for the other formats.

7. CWELD defines a flexible connection between two surface patches, between apoint and a surface patch, or between two shell vertex grid points. See Figure6-3 through Figure 6-5.

Figure 6-3. Patch-to-Patch Connection Defined with Format GRIDID orELEMID


Figure 6-4. Point-to-Patch Connection Defined with Format GRIDID orELEMID

Figure 6-5. Point-to-Point Connection Defined with Format ALIGN

8. Forces and moments are output in the element coordinate system. The elementx-axis is in the direction of GA to GB, see Figure 6-6. If zero length (GA andGB are coincident), the x-axis will be defined by the normal from shell A. Theelement y-axis is perpendicular to the element x-axis and is lined up with theclosest axis of the basic coordinate system. The element z-axis is the crossproduct of the element x- and y-axis. The output of the forces and momentsincluding the sign convention is the same as in the CBAR element.

182 CFASTDefines a shell patch connection.

fx— Axial force

fy — Shear force, plane 1

fz — Shear force, plane 2

mx— Torque

MyA— Bending moment end A, plane 2

MyB— Bending moment end B, plane 2

MzA— Bending moment end A, plane 1

MzB— Bending moment end B, plane 1

Figure 6-6. Element Coordinate System and Sign Convention of ElementForces

9. When the format is “ELPAT” or “PARTPAT”, the displacement results at GAand GB are always output to the .f06 file regardless of the case control options.Since grid points do not typically exist at these locations, grid numbers areautomatically generated using:Grid ID = 1000000 + 10*(cweld ID) + (end ID)where the end ID is 1 or 2 for the two ends.The new grid ID’s are only used for labeling the displacement output and do notexist in the analysis or internal tables. This displacement result is not written tothe .op2 or punch file.

CFAST Defines a shell patch connection.

Defines a shell patch connection with direct stiffness input.

CFAST 183Defines a shell patch connection.

Format:

1 2 3 4 5 6 7 8 9 10

CFAST EID PID TYPE IDA IDB GS GA GB

XS YS ZS

Example using PROP:

1 2 3 4 5 6 7 8 9 10

CFAST 10 25 PROP 2 4 105

Example using ELEM:

1 2 3 4 5 6 7 8 9 10

CFAST 10 25 ELEM 36 46 105

Fields:

Field Contents

EID Element identification number. (Integer > 0)

PID Property identification number of a PFAST bulk data entry (Integer> 0; Default = EID)

TYPE Determines if shell element patches A and B are defined by elementor property identification numbers. (Character)

If TYPE = ‘PROP’, IDA,IDB define pshell property identificationnumbers.

If TYPE = ‘ELEM’, IDA,IDB define shell element identificationnumbers.

IDA,IDB Property id (for type PROP) or Element id (for type ELEM) definingpatches A and B. IDA and IDB should be unique. (Integer > 0)

GS Grid point used to determine the location of the connection on patchesA and B, only when GA,GB are blank or 0. See Remark 2 . (Integer >0 or blank)

GA,GB Grid point used to determine the location of the connection on patchesA and B. See Remark 2 . (Integer > 0 or blank)

184 CFASTDefines a shell patch connection.

Field Contents

XS,YS,ZS Determines the coordinate location of the connection on patches Aand B, only if GA,GB,GS are all 0 or blank. See Remark 2 . (Real orblank)

Remarks:

1. The CFAST defines a weld like connection between two shell element patches.The CFAST element is similar to the CWELD element, except that the CFASTstiffness is entered directly on the KTi and KRi fields of the PFAST entry.

2. GA/GB, or GS, or XS/YS/ZS, in that order of precedence, determine the location(s)of the CFAST connection on surface patches A and/or B. The connection locationon patch A is a specification of grid point GA, or a projection of GS or XS/YS/ZSnormal to surface patch A. The location on patch B is a specification of gridpoint GB, or a projection of GS or XS/YS/ZS normal to surface patch B. WhenGS or XS/YS/ZS are used, a normal projection must exist in order to define avalid connection element. GS or XS/YS/ZS do not need to lie on either surfacepatch A or B.

3. The displacement results at GA and GB are always output to the .f06 fileregardless of the case control options. Since grid points do not typically exist atthese locations, grid numbers are automatically generated using:Grid ID = 1000000 + 10*(cfast ID) + (end ID)where the end ID is 1 or 2 for the two ends.The new grid ID’s are only used for labeling the displacement output and do notexist in the analysis or internal tables. This displacement result is not written tothe .op2 or punch file.

4. The displacement coordinate system for all grids connected to a CFAST patchmust be the basic system (default).

Chapter

7 DMP Enhancements

186 New Multilevel RDMODES

7.1 New Multilevel RDMODESIn NX Nastran 6.0, the Recursive Domain Lanczos method (RDMODES) wasintroduced to extend the DMP parallel capability via substructuring technologyfor very large scale normal modes solutions. Compared to standard Lanczosapproaches, the RDMODES approach generally computes fewer modes with loweraccuracy in order to gain performance.

In this release, a new multilevel RDMODES option has been added to enhanceperformance, and is used by default when RDMODES is activated. The optionalkeyword “nclust” activates the original single-level RDMODES.

Inputs

Multilevel RDMODES is activated by nastran keywords dmp and nrec:

NASTRAN dmp=p nrec=m

where p is the number of processors and m is the number of external partitions.

Single-level RDMODES is activated when the keyword nclust is present:

NASTRAN dmp=p nrec=m nclust=c

where c is the number of clusters.

Remarks

1. The optional keyword rdscale is a factor to modify the selected frequencyrange in the EIGRL specification for eigensolutions of each substructure. Thedefault value of rdscale is 2.0 for the multilevel RDMODES, and 1.0 for thesingle-level RDMODES.

2. Currently only MLV partitioning is available to create substructures for themultilevel method.

Example

• Car body model with 268,486 grid points, 275,660 elements, 1,584,622 degreesof freedom

• up to 200 Hz frequency

• 16 node Linux Opteron cluster

The following table compares a multilevel RDMODES run (dmp=16, nrec=128)with a single-level RDMODES run (dmp=16, nrec=128, nclust=16). For reference,an HDMODES run (dmp=16, nclust=4), and a serial run (without DMP) is alsoincluded.

GDMODES Performance 187

Method Modesfound

MemoryMW

Elapsedmin:sec

CPUSeconds

I/OGBytes

DiskGBytes

MultilevelRDMODES

1032 122.2 47.17 546.7 98.7 15.4

Single-levelRDMODES

888 122.2 68:18 1123.4 142.7 14.2

HDMODES 1073 122.2 85:44 2711.5 325.4 19.8

Serial 1073 117.9 721:11 16,979.8 2476.6 43.9

Note that the new multilevel RDMODES found 10% more modes than thesingle-level RDMODES with a 40% reduction in elapsed time and 30% reductionin I/O usage.

The multilevel RDMODES finds more modes than the single-level RDMODESbecause the default rdscale value is 2.0 instead of 1.0 used in the single-levelRDMODES. See the NX Nastran 6.0 Parallel Processing Guide and Release Guidefor more information on RDMODES.

7.2 GDMODES PerformanceIn the parallel processing of a finite element application, finite element model datais distributed to each processor. There are two different methods for partitioning ina Geometric Domain Normal Modes Analysis (GDMODES): grid-based partitioningand degree of freedom-based partitioning. The module SEQP performs grid-basedpartitioning, in which p domains are created by an automatic partitioner from thegrid-based graph. The module GPARTN performs graph partitioning for the graphbased on degrees-of-freedom.

The partitioning method is selected by the nastran command keyword ‘gpart’:

Keyword Modulegpart = 0 (default) SEQPgpart = 1 GPARTN

With either of these modules, there are optional algorithms for partitioning, whichcan be selected with the parameter oldseq.

188 GDMODES Performance

In this release, a new grid compression option has been added to the GPARTNmodule. For some models, grid compression produces a smaller global boundary,resulting in much improved eigensolver performance.

The updated PARAM,OLDSEQ options for GPARTN are:

OLDSEQ Description10 Metis with supernodal and grid compression

11 MLV with supernodal and grid compression

110 Metis with supernodal compression

111 MLV with supernodal compression

210 Metis with grid compression

211 MLV with grid compression

In addition the module GMERGE, which gathers solution results for each geometrypartition, is now more efficient such that network communication is reduced.

Remarks

1. If at least two processors are available and both supernodal and gridcompression are requested (OLDSEQ=10 or 11), then GPARTN selects thecompression resulting in the smallest global boundary size.

2. The default OLDSEQ value is 11. System (294) = 1 prints new diagnosticinformation to the f06 file.

Example

• Box beam model

• 268,802 grid points, 268,800 elements, 1,612,812 degrees of freedom

• Up to 200 Hz frequency

• 64 node Linux Opteron cluster

The results summary below compares GDMODES runs (dmp=16, gpart=1) withand without the enhancements.

1. GPARTN enhancement:

The original GPARTN uses only supernodal compression, and produces alarge boundary size of 331,728. As a result, the eigensolver (READ module) inGDMODES took more than 700 minutes.

In this extreme case, the new grid compression produces a smaller boundarysize of 23,916. As a result, this GPARTN enhancement reduces the eigensolvertime in GDMODES to about 21 minutes (more than 30 times faster).

GDMODES Performance 189

2. GMERGE enhancement:

With the new network communication, the GMERGE module takes 1 minute13 seconds, about 5 times faster than before (6 minutes 17 seconds).

Chapter

8 Numerical Enhancements

192 Introduction

8.1 IntroductionThe matrix multiply-add operation is conceptually simple, however, the widevariety of matrix characteristics and type combinations require a multitude ofmethods. These methods are constantly evaluated and improved, mostly toimprove the performance of the millions of matrix operations that may occur ina single solution.

The matrix multiply-add modules MPYAD and SMPYAD have been improved inthis release, which evaluate the following equations:

MPYAD evaluates [D] = +/-[A](T) [B] +/- [C]

SMPYAD evaluates [G] = [A](T) [B](T) [C](T) [D](T) E +/- F

The full details of these modules are described in chapter 2, of the NX NastranNumerical Methods User’s Guide. The specific enhancements for the NX Nastran6.1 release are described as follows.

8.2 MPYAD ImprovementA new submethod of MPYAD method 1 has been added. The submethod, calledStorage 3, will be automatically selected by default if it is the fastest according totime estimates. You can also select or deselect the submethod with system cell 66.

Deselection and selection options:

System cell 66 Method67108864 Deselection of method 1 storage 3 NT

134217728 Deselection of method 1 storage 3 T

1048602 Selection of method 1 storage 3 NT

1048603 Selection of method 1 storage 3 T

Remark:

The submethod uses level-3 BLAS (Basic Linear Algebra Subroutine) kernels.Generally, it is selected for dense matrices MPYAD.

Example:

• Dense Matrix A: 3000 × 3000

• Dense Matrix B: 3000 × 8000

• 40MB memory

• Aix Power 5

SMPYAD Improvement 193

NXN 6.0 Storage 2(cpu seconds)

NXN 6.1 Storage 3 (cpuseconds)

Nontranspose: AB 90.4 29.8Transpose: ATB 44.7 29.1

Cpu time for MPYAD is saved significantly from the previous version. Theperformance of storage 2 in NXN 6.1 on Aix is also improved.

8.3 SMPYAD ImprovementA new triple-multiply option is added to SMPYAD. The new triple-multiply isdesigned for a dense middle matrix, while the old version is for a sparse middlematrix. The triple-multiply option will be automatically selected as the fastestmethod based on time estimates, or controlled manually with system cell 129.

The triple-multiply options are listed below:

System cell 129 Triple-multiply options

0 (default) Default, automatic selection1 Two MPYAD2 Triple multiply for sparse middle matrix

3 Triple multiply for dense middle matrix

Example

• Dense Matrix A: 3000 × 2000

• Dense Matrix B: 3000 × 3000

• 40MB memory

• Aix Power 5

NXN 6.0 Triple-Multiply(cpu seconds)

NXN 6.1 Triple-Multiply(cpu seconds)

ATBA 25.3 10.5

Chapter

9 Acceleration Loads

196 Acceleration Load Enhancements

9.1 Acceleration Load EnhancementsThe current GRAV bulk entry defines a uniform gravity/acceleration field, whichresults in a static load applied to each grid that has an associated mass. Theassociated mass at a grid is calculated from both the element structural and anynonstructural mass if defined.

In NX Nastran 6.1, two new bulk entries have been added to expand thegravity/acceleration options.

The new ACCEL bulk entry is similar to the GRAV bulk entry since it defines anacceleration field which applies to all grids in the model with an associated mass.In addition, the ACCEL bulk entry also has the option to vary the field in a singlecoordinate direction with a scale factor.

The new ACCEL1 bulk entry is unique since it defines a constant accelerationvector, which is applied at specific GRID IDs, and is not an acceleration field likethe GRAV and ACCEL bulk entries define. The THRU and BY keywords canbe used to define the list of grid IDs.

You can use ACCEL and ACCEL1 in any solution sequences that support theLOAD case control command, except for solutions 601 and 701. Multiple loadtypes, including GRAV, ACCEL, ACCEL1, FORCE, etc., can be combined in asingle subcase using the LOAD bulk entry, if their load IDs are unique.

Acceleration Load Examples

GRAV Example

The GRAV bulk entry defines a uniform gravity/acceleration field.

The GRAV bulk entry has the format:

1 2 3 4 5 6 7 8 9 10

GRAV SID CID A N1 N2 N3 MB

The coordinate system shown has an id of 3 (CID=3), the gravity vector has amagnitude of 32.2 (A=32.2), and is in the -Z direction (N1=0.0, N2=0.0, N3=-1.0).All grids in the model will receive the gravity load.

Acceleration Load Enhancements 197

The example input:

GRAV 1 3 32.2 0.0 0.0 -1.0

The gravity vector magnitude is the magnitude of N1,N2,N3 multiplied by thescale factor A. For example, you could also enter (N1=0.0, N2=0.0, N3=-32.0) forthe vector and A=1 to get the same result.

ACCEL Example

The new ACCEL bulk entry defines an acceleration field which can optionallyvary in a single coordinate direction.

The ACCEL bulk entry has the format:

1 2 3 4 5 6 7 8 9 10

ACCEL SID CID N1 N2 N3 DIR

LOC1 VAL1 LOC2 VAL2 Continues in Pairs

The coordinate system shown has an id of 3 (CID=3), the linearly varyingacceleration field is in the -Z direction (N1=0.0, N2=0.0, N3=-1.0), and varies in theX-direction (DIR=”X”). Since the field in this example varies linearly, only 2 scalevalues are needed to vary the field for the entire model, and values are linearlyinterpolated at grids in between the defined LOCi/VALi pairs.

The model is a 6.0 x 6.0 square. At X=0.0, the acceleration scale is 32.2, and atX=6.0. the acceleration scale is 10.2.

198 Acceleration Load Enhancements

Therefore, grids 16,9,10,15 will receive an acceleration of –32.2,grids 6,2,1,12 will receive an interpolated value of –24.9,grids 5,4,3,11 will receive an interpolated value of –17.5,and grids 13,7,8,14 will receive a value of –10.2.

The resulting acceleration, multiplied by the associated mass will determine thespecific load at each grid.

The example input:

ACCEL 1 3 0.0 0.0 0.0 -1.0

0.0 32.2 6.0 10.2

ACCEL1 Example

The ACCEL1 bulk entry defines an acceleration on specific grids.

The ACCEL1 bulk entry has the format:

1 2 3 4 5 6 7 8 9 10

ACCEL1 SID CID A N1 N2 N3

GRIDID1 GRIDID2 -etc.-

Acceleration Load Enhancements 199

The coordinate system shown has an id of 3 (CID=3), the gravity vector has amagnitude of 32.2 (A=32.2), and is in the -Z direction (N1=0.0, N2=0.0, N3=-1.0).Only grids 4, 5, 7, and 13 receive the gravity load.

The example input:

ACCEL1 1 3 32.2 0.0 0.0 -1.0

4 5 7 13

The acceleration vector magnitude is the magnitude of N1,N2,N3 multiplied by thescale factor A. For example, you could also enter (N1=0.0, N2=0.0, N3=-32.0) forthe vector and A=1 to get the same result.

200 ACCEL

New ACCEL and ACCEL1 Bulk Entries

ACCEL

Defines a static acceleration load field, which may vary the field at specificcoordinate locations in a coordinate direction.

Format:

1 2 3 4 5 6 7 8 9 10

ACCEL SID CID N1 N2 N3 DIR

LOC1 VAL1 LOC2 VAL2 Continues in Pairs

Example:

ACCEL 1 3 0.0 0.0 0.0 -1.0

0.0 32.2 6.0 10.2

Fields:

Field Contents

SID Load set identification number. (Integer>0)

CID Coordinate system identification number. (Integer>0: Default=0)

Ni Components of the acceleration vector measured in coordinatesystem CID. (Real; at least one Ni ≠ 0.0 )

DIR Component direction of acceleration variation. (Character; one of X,Y or Z)

LOCi Location along direction DIR in coordinate system CID forspecification of a load scale factor. (Real)

VALi The load scale factor associated with location LOCi. (Real)

Remarks:

1. ACCEL is similar to the GRAV bulk entry since it defines an accelerationfield which applies to all grids in the model with an associated mass, exceptACCEL also has the option to vary the field at specific coordinate locations in acoordinate direction using the fields DIR, LOCi, and VALi.

2. For all grids of the model, the acceleration vector is defined by:where is the vector defined by (N1, N2, and N3). The magnitude of is equal

ACCEL 201

to VAL times the magnitude of . The scale factor VAL for each grid is foundby linearly interpolating the DIR coordinate of the grid between table valuesLOCi/VALi. If the GRID point coordinate in coordinate system CID is outsidethe range of the table, VAL is determined from the closer of VAL1 or VALn. (Seethe figure below the remarks).

3. ACCEL can be used in any solution sequences which support the LOAD casecontrol command, except for solutions 601 and 701. Multiple load types,including GRAV, ACCEL, ACCEL1, FORCE, etc., can be combined in a singlesubcase using the LOAD bulk entry, if their load id’s are unique.

4. ACCEL does not include effects due to mass on scalar points.

5. A blank CID entry or a CID of zero references the basic coordinate system.

6. The DIR field must contain one of the characters X, Y, or Z. The DIR directiondefines the direction of acceleration load variation along direction 1, 2, or 3respectively of coordinate system CID.

7. At least two pairs of {LOCi, VALi} must be specified when varying the field.

202 ACCEL1

ACCEL1

Defines static acceleration loads at individual grid points.

Format:

1 2 3 4 5 6 7 8 9 10

ACCEL1 SID CID A N1 N2 N3

GRIDID1 GRIDID2 -etc.-

Example:

ACCEL1 100 2 100.0 0.0 1.0 0.0

1 2 3 4 5 6 7 8

9 10 THRU 100 BY 5 200 250

Fields:

Field Contents

SID Load set identification number. (Integer>0)

CID Coordinate system identification number. (Integer>0: Default=0)

a Acceleration vector scale factor. (Real)

Ni Components of the acceleration vector measured in coordinatesystem CID. (Real; at least one Ni ≠ 0.0 )

GRIDIDi List of one or more GRID point identification numbers. Key words“THRU” and “BY” can be used to assist the listing. (Integer>0)

Remarks:

1. The acceleration vector is defined by , where is the vector (N1, N2, andN3). The magnitude of is equal to A times the magnitude of .

2. ACCEL1 can be used in any solution sequences which support the LOADcase control command, except for solutions 601 and 701. Multiple load types,including GRAV, ACCEL, ACCEL1, FORCE, etc., can be combined in a singlesubcase using the LOAD bulk entry, if their load id’s are unique.

3. ACCEL1 does not include effects due to mass on scalar points.

4. A blank CID entry or a CID of zero references the basic coordinate system.

ACCEL1 203

5. The ACCEL1 entry must contain at least one GRIDID.

Chapter

10 Improved RMAXMIN Output

206 RMAXMIN Output Enhancements

10.1 RMAXMIN Output EnhancementsThe RMAXMIN case control command is used with a modal transient solution(SOL 112) to evaluate the maximum or minimum force, stress, and displacementcomponents at each output grid or element over an entire time history. In additionto the maximum/minimum output, an RMS for each component of force, stress, anddisplacement is also calculated and output.

An example of the maximum and RMS displacement results written to the f06file is:

In the op2 results file, the RMAXMIN output is written to the OUGV1MXdatablock for displacement, OES1MX datablock for stress, and the OEF1MXdatablock for force.

In NX Nastran 6.1, the RMAXMIN case control command has been enhanced:

• RMAXMIN is now supported in a direct transient solution (SOL 109).

• New START and END inputs on RMAXMIN limit the evaluation over aspecific range in the time history.

• New NPAVG input on RMAXMIN is the number of peaks in the time history tobe averaged for output. Previously only the single highest peak was output.This now corresponds to NPAVG=1, the default setting for NPAVG.

• The new input RMXTRN on RMAXMIN turns on/off the normal printing oftransient output data when RMAXMIN is used. The value defined on theRMAXMIN case control works the same as the parameter RMXTRN, andtakes precedence over the parameter. By default, RMXTRN=NO, and onlyRMAXMIN data is output.

The TIME input is not significant for the RMAXMIN output since the data isevaluated over the entire time history.

RMAXMIN Output Enhancements 207

RMAXMIN Example

Updated RMAXMIN format:

Consider a transient time history that runs from time 0.0 to 1.6 and the computedstress components of an element are given in the table below.

Stress Output Example: (this data represents the complete time history for asingle element)

Time Normal X at Z1 Normal Y at Z1 Normal XYat Z1 VonMises at Z1

0.0 0.0 0.0 0.0 0.00.1 1.0 0.0 4.0 7.00.2 2.0 -1.0 8.0 14.10.3 1.0 4.0 3.0 6.30.4 3.0 –2.0 -6.0 11.30.5 5.0 5.0 0.0 5.00.6 7.0 –1.0 4.0 10.20.7 3.0 6.0 0.0 5.20.8 –6.0 9.0 6.0 16.70.9 6.0 4.0 9.0 16.51.0 1.0 –8.0 3.0 10.01.1 4.0 3.0 8.0 14.31.2 7.0 6.0 0.0 6.61.3 4.0 1.0 3.0 6.31.4 6.0 3.0 2.0 6.21.5 –7.0 2.0 5.0 11.91.6 2.0 1.0 0.0 1.7

Example Input 1:

STRESS = ALLRMAXMIN(STRESS,PRINT,MAX,NPAVG=3,START=.3,END=1.2) = yes


Since the RMAXMIN input is requesting MAX, NPAVG=3, and a start and endtime range, the three maximum values within the specified time range areaveraged, and reported in the “Table of Maximum Values” in the *.f06 outputfor each element requesting output. The highlighted cells in each column aboverepresent the three maximum peak responses to be averaged within the START –END time range of .3 to 1.2. The data output by RMAXMIN is:

RMAXMINResult Normal X at Z1 Normal Y at Z1 Normal XY

at Z1 VonMises at Z1

Maximum 6.67 6.67 7.00 14.10RMS 4.81 5.37 5.01 11.06

The figures below show the time history plot of each component and the threeidentified maximum peaks used for averaging are indicated. Note that theRMAXMIN algorithm does not find the highest responses for averaging, but thehighest peak responses.

Normal Stress X at Z1

RMAXMIN Output Enhancements 209

Normal Stress Y at Z1

Shear Stress XY at Z1

Von Mises Stress at Z1

Example Input 2:


If the NPAVG, START, and END options are not specified the output request is:

STRESS = ALLRMAXMIN(STRESS,PRINT,MAX) = yes

Using the same transient as above, the RMAXMIN results would be:

RMAXMINResult Normal X at Z1 Normal Y at Z1 Normal XY

at Z1 VonMises at Z1

Maximum 7.00 9.00 9.00 16.70RMS 4.48 4.23 4.66 9.98

Updated RMAXMIN Case Control Command 211Requests MIN/MAX values from solution 109 and 112 sort1 output.

Updated RMAXMIN Case Control Command RequestsMIN/MAX values from solution 109 and 112 sort1 output.

Defines parameters to output the minimum, maximum, absolute value maximum,and RMS response of stress, force and displacement sort1 results generated duringsolutions 109 and 112.

Format:

Examples:

RMAXMIN(NOPRINT,STRESS,ABSOLUTE)=YESRMAXMIN(STRESS,PRINT,MAX,NPAVG=3,START=.3,END=1.2) = yes

Describers:

Describer Meaning

FORCE, STRESS,DISP

Result tables to be searched.

PRINT Writes output to the print file. (Default)

NOPRINT Does not write output to the print file.

PUNCH Writes output to the punch file.

PLOT Writes output to .plt file.

ABSOLUTE Specifies output of absolute maximum values.

MINIMUM Specifies output of minimum values.

MAXIMUM Specifies output of maximum values. (Default)

RMXTRAN Turns on or off the normal printing of transient outputdata when RMAXMIN output is requested. See Remark4.

212 Updated RMAXMIN Case Control CommandRequests MIN/MAX values from solution 109 and 112 sort1 output.

Describer Meaning

YES Transient results will be output according to theDISPLACEMENT, STRESS, and FORCE case controlentries.

NO Transient results are not output if RMAXMIN isactivated.

NPAVG Number of peaks in the time history to be averaged.When NPAVG=1 (default), only the single highest peakis output.

START=a,END=b Limits the RMAXMIN evaluation over a specific rangein the time history. See Remark 7.

YES Activates RMAXMIN.

NO Disables RMAXMIN.

Remarks:

1. Only one of MAXIMUM, MINIMUM and ABSOLUTE can be selected. RMSvalues are always output with any of the selections.

2. Since RMAXMIN only processes SORT1 output requests, you must specifyPARAM, POST in conjunction with RMAXMIN to process the OEF1, OES1 orOUGV1 datablocks.

3. One or more of STRESS, FORCE and DISP must be selected for any output to begenerated. RMAXMIN processes displacement for the grid points specified bythe DISP case control and processes stress and force for elements specified bythe STRESS and FORCE case control respectively.

4. The parameter RMXTRAN can also be used to control the output of transientresults for STRESS, FORCE, DISP case control when RMAXMIN is activated,but only if the RMXTRAN input on RMAXMIN is not defined. The parameterdefault, RMXTRAN=NO will suppress output of transient results. TheRMXTRAN describer on the RMAXMIN case control command, when defined,takes precedence over the RMXTRAN parameter.

5. The output datablocks generated by RMAXMIN are OES1MX, OEF1MX, andOUGV1MX for stress, force and displacement respectively.

6. The maximum, minimum, absolute, and RMS results are captured and storedon a component basis in the OES1MX, OEF1MX, and OUGV1MX datablocks.

Updated RMAXMIN Case Control Command 213Requests MIN/MAX values from solution 109 and 112 sort1 output.

For example, the maximum displacement is computed and stored for each of agrid’s six DOF and each value may correspond to different times in the transienthistory.

7. The START=a and END=b describers can be used to limit the RMAXMINevaluation to a specific time range. By default, START is the beginning, andEND is the final time in the transient, such that one can be defined without theother. For example, if a full transient is from 1 to 100 seconds, START=20 willevaluate the RMAXMIN output in the 20 to 100 second range.

Chapter

11Pyramid Element VerificationTest Results

216 Summary

11.1 SummaryThe following solid element test cases are part of the NX Nastran VerificationManual and have been updated with results for the new solid pyramid element.These results will also be included in the NX Nastran 7 Verification Manual.

11.2 Solid Cylinder/Taper/Sphere — TemperatureThis test is a linear elastic analysis of a solid cylinder with a temperature gradient(shown below) using coarse and fine meshes of solid elements. It provides the inputdata and results for NAFEMS Standard Benchmark Test LE11.

Solid Cylinder/Taper/Sphere — Temperature 217

Test Case Data and Information

Input Files

• le1101a.dat (linear brick — coarse mesh)

• le1101b.dat (linear brick — fine mesh)

• le1102a.dat (parabolic brick — coarse mesh)

• le1102b.dat (parabolic brick — fine mesh)

• le1103a.dat (linear wedge — coarse mesh)

• le1103b.dat (linear wedge — fine mesh)

• le1104a.dat (parabolic wedge — coarse mesh)

• le1104b.dat (parabolic wedge — fine mesh)

• le1105a.dat (linear tetra — coarse mesh)

• le1105b.dat (linear tetra — fine mesh)

• le1106a.dat (parabolic tetra — coarse mesh)

• le1106b.dat (parabolic tetra — fine mesh)

• le1107a.dat (linear pyramid — coarse mesh)

• le1107b.dat (linear pyramid — fine mesh)

• le1108a.dat (parabolic pyramid — coarse mesh)

• le1108b.dat (parabolic pyramid — fine mesh)

Physical and Material Properties

• Isotropic material

• E = 210E3 MPa

• v = 0.3

• a = 2.3E–4 °C

218 Solid Cylinder/Taper/Sphere — Temperature

Units

SI

Finite Element Modeling

• Solid brick (CHEXA) linear and parabolic — coarse and fine mesh

• Solid wedge (CPENTA) linear (6 grid point) and parabolic (15 grid point) —coarse and fine mesh

• Solid tetrahedron (CTETRA) linear and parabolic — coarse and fine mesh

• Solid pyramid (CPYRAM) linear and parabolic — coarse and fine mesh (createdby dividing each linear and parabolic brick element into 6 pyramid elements)

Solid Brick


Solid Tetrahedron

220 Solid Cylinder/Taper/Sphere — Temperature

Boundary Conditions

• Linear temperature gradient in the radial and axial direction

T° C = (X2 + Y2)1/2 + Z

• X, Y, and Z displacements = 0

• X and Y displacements on face BCB¢C¢ are fixed

• Z displacements on XY-plane face and HIH¢I¢ face = 0

Solution Type

SOL 101 — Linear Statics

Results

Output - direct stress syy at point A

File Name Result Grid point atPoint A

BenchValue

NXNastran

le1101a Linear brick —coarse mesh

30 –105.0 –88.29


File Name Result Grid point atPoint A

BenchValue

NXNastran

le1101b Linear brick — finemesh

71 –105.0 –93.68

le1102a Parabolic brick —coarse mesh

67 –105.0 –100.4

le1102b Parabolic brick —fine mesh

159 –105.0 –111.2

le1103a Linear wedge —coarse mesh

33 –105.0 –10.00

le1103b Linear wedge —fine mesh

74 –105.0 –48.30

le1104a Parabolic wedge —coarse mesh

71 –105.0 –87.20

le1104b Parabolic wedge —fine mesh

187 –105.0 –96.20

le1105a Linear tetra —coarse mesh

8 –105.0 –31.40

le1105b Linear tetra — finemesh

8 –105.0 –65.20

le1106a Parabolic tetra —coarse mesh

8 –105.0 –89.60

le1106b Parabolic tetra —fine mesh

8 –105.0 –97.30

le1107a Linear pyramid —coarse mesh

30 –105.0 –57.00

le1107b Linear pyramid —fine mesh

71 –105.0 –79.80

le1108a Parabolic pyramid— coarse mesh

67 –105.0 –65.8

le1108b Parabolic pyramid— fine mesh

159 –105.0 –109.0

References

NAFEMS Finite Element Methods & Standards. The Standard NAFEMSBenchmarks, Test No. LE11. Glasgow: NAFEMS, Rev. 3, 1990.

222 Thick Plate Pressure

11.3 Thick Plate PressureThis article provides the input data and results for NAFEMS Standard BenchmarkTest LE10. This test is a linear elastic analysis of a thick (shown below) usingcoarse and fine meshes of solid elements.

Ellipses:


Input Files

• le1001.dat (linear and parabolic brick)

• le1002.dat (linear and parabolic wedge)

• le1003.dat (linear and parabolic tetrahedron)

• le1004.dat (linear and parabolic pyramid)

Physical and Material Properties

• Isotropic material

Thick Plate Pressure 223

• E = 210E3 MPa

• v = 0.3

Units

SI


• Solid brick (CHEXA) linear and parabolic - coarse and fine mesh

• Solid wedge (CPENTA) linear and parabolic - coarse and fine mesh

• Solid tetrahedron (CTETRA) - linear and parabolic - coarse and fine mesh

• Solid pyramid (CPYRAM) linear and parabolic - coarse and fine mesh (createdby dividing each linear and parabolic brick element into 6 pyramid elements)

Solid Brick


Solid Wedge


Solid Tetrahedron — fine mesh only

Boundary Conditions

• Uniform normal pressure on the upper surface of the plate = 1 MPa

• Inner curved edge AD unloaded

• X and Y displacements on faces DCD’C¢ and ABA¢B¢ = 0

• X and Y displacements on face BCB¢C¢ are fixed

• Z displacements along mid-plane are fixed


Solution Type


Results

Output — direct stress at point Dsyy

Test Case le1001

Mesh Grid point # Bench Value NX Nastran

Linear brick — coarsemesh

4 –5.500 –5.410

Linear brick — fine mesh 204 –5.500 –5.670

Parabolic brick — coarsemesh

104 –5.500 –6.130

Parabolic brick — finemesh

304 –5.500 –6.040

Test Case le1002


Linear wedge — coarsemesh

4 –5.500 –5.940



Linear wedge — fine mesh 204 –5.500 –5.830

Parabolic wedge — coarsemesh

104 –5.500 –5.320

Parabolic wedge — finemesh

304 –5.500 –6.010

Test Case le1003

Result Grid point # Bench Value NX Nastran

Linear tetra — fine mesh 40 –5.500 –2.410

Parabolic tetra — finemesh

171 –5.500 –5.280

Test Case le1004


Linear pyramid— coarsemesh

4 –5.500 –2.850

Linear pyramid — finemesh

204 –5.500 –3.830

Parabolic pyramid —coarse mesh

104 –5.500 –5.600

Parabolic pyramid —fine mesh

304 –5.500 –5.720

References

NAFEMS Finite Element Methods & Standards. The Standard NAFEMSBenchmarks, Test No. LE10. Glasgow: NAFEMS, Rev. 3, 1990.

228 Deep Simply Supported "Solid" Beam

11.4 Deep Simply Supported "Solid" BeamThis test is a normal mode dynamic analysis of a deep, simply supported beammeshed with solid elements. This document provides the input data and results forNAFEMS Selected Benchmarks for Natural Frequency Analysis , Test 51.

Attributes of this test are:

• Skewed coordinate system

• Skewed restraints


• nf051a.dat (linear brick)

• nf051b.dat (parabolic brick)

• nf051c.dat (linear pyramid)

• nf051d.dat (parabolic pyramid)

UnitsSI

Material Properties• E = 200E09 N/m2

• r = 8000 kg/m3

Deep Simply Supported "Solid" Beam 229

• n = 0.3


Four tests:

• 30 solid linear brick (CHEXA) elements

• 5 solid parabolic brick (CHEXA) elements

• 180 solid linear pyramid (CPYRAM) elements (created by dividing each linearbrick element into 6 pyramid elements)

• 30 solid parabolic pyramid (CPYRAM) elements (created by dividing eachparabolic brick element into 6 pyramid elements)

Boundary Conditions

• X¢ = Z¢ = 0 along AA¢

• Z¢ = 0 along BB¢

• Y¢ = 0 at all grid points on the plane Y¢ = 2.0 m

230 Deep Simply Supported "Solid" Beam

Solution Type

SOL 103 — Normal Mode Dynamics

NX Nastran results were obtained two different ways:

• Using lumped mass (param coupmass = –1)

• Using coupled mass (param coupmass = 1)

Results

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTarget

Value (Hz)

NXNastranResult(lumpedmass) (Hz)

NX NastranResult(coupledmass) (Hz)

1 38.20 linear brick

linear pyramid

parabolic brick

parabolic pyramid

42.88

38.82

37.96

41.30

37.85

37.90

38.28

41.50

38.24

38.10

Deep Simply Supported "Solid" Beam 231

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTarget

Value (Hz)

NXNastranResult(lumpedmass) (Hz)



linear pyramid

parabolic brick

parabolic pyramid

93.82

88.45

83.38

89.30

87.12

86.30

83.95

89.60

87.52

86.50


linear pyramid

parabolic brick

parabolic pyramid

170.7

159.4

152.7

163.0

151.8

152.0

157.6

166.0

157.0

155.0


linear pyramid

parabolic brick

parabolic pyramid

286.1

259.2

251.6

269.0

248.5

250.0

264.9

276.0

258.2

255.0


linear pyramid

parabolic brick

parabolic pyramid

318.9

307.9

288.0

303.0

289.6

291.0

298.3

309.0

305.6

300.0

Note

The reference value refers to the accepted solution to the problem.

References

NAFEMS Finite Element Methods & Standards, Abbassian, F., Dawswell, D. J.,and Knowles, N. C., Selected Benchmarks for Natural Frequency Analysis TestNo. 51. Glasgow: NAFEMS, Nov., 1987.

232 Simply Supported "Solid" Square Plate

11.5 Simply Supported "Solid" Square PlateThis test is a normal mode dynamic analysis of a simply supported square platemeshed with solid elements. This document provides the input data and results forNAFEMS Selected Benchmarks for Natural Frequency Analysis, Test 52.


• Well established

• Rigid body modes (three modes)

• Kinematically incomplete suppressions


• nf052l.dat (linear brick)

• nf052b.dat (parabolic brick)



UnitsSI

Material Properties• E = 200E09 N/m2

• r = 8000 kg/m3

• n = 0.3

Simply Supported "Solid" Square Plate 233


Four tests:

• 64 solid linear brick (CHEXA) elements

• 16 solid parabolic brick (CHEXA) elements



Boundary Conditions

Z = 0 along the four edges on the plane Z = –0.5 m


Solution Type

SOL 103 normal modes

NX Nastran results were obtained in two different ways:



Results

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTargetValue(Hz)

NX NastranResult(lumpedmass) (Hz)



linear pyramid

parabolic brick

parabolic pyramid

51.65

44.76

44.04

66.90

43.81

44.70

45.24

68.00

44.16

44.80

Simply Supported "Solid" Square Plate 235

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTargetValue(Hz)



5, 6 109.4 linear brick

linear pyramid

parabolic brick

parabolic pyramid

132.7

110.5

106.5

154.0

105.2

109.0

113.7

160.0

107.9

110.0


linear pyramid

parabolic brick

parabolic pyramid

194.4

169.1

155.5

195.0

156.3

166.0

172.3

197.0

163.9

169.0


linear pyramid

parabolic brick

parabolic pyramid

197.2

193.9

193.6

207.0

194.0

194.0

196.8

212.0

193.9

194.0


linear pyramid

parabolic brick

parabolic pyramid

210.6

206.6

200.1

207.0

193.5

196.0

209.6

212.0

206.6

207.0


linear pyramid

parabolic brick

parabolic pyramid

210.6

206.6

200.1

220.0

193.5

196.0

209.6

223.0

206.6

207.0

Note

The reference value refers to the accepted solution to the problem.


References

NAFEMS Finite Element Methods & Standards, Abbassian, F., Dawswell, D. J.,and Knowles, N. C. Selected Benchmarks for Natural Frequency Analysis, TestNo. 52. Glasgow: NAFEMS, Nov., 1987.

Simply Supported "Solid" Annular Plate 237

11.6 Simply Supported "Solid" Annular PlateThis test is a normal mode dynamic analysis of a simply supported annular platemeshed with solid elements. This document provides the input data and results forNAFEMS Selected Benchmarks for Natural Frequency Analysis, Test 53.


• Curved boundary (skewed coordinate system)

• Constraint equations


• nf053l.dat (linear brick)

• nf053h.dat (parabolic brick)



Units

SI

Material Properties

• E = 200E09 N/m2

• r = 8000 kg/m3

• n = 0.3

238 Simply Supported "Solid" Annular Plate


Four tests:

• 60 solid linear brick (CHEXA) elements — a = 5°

• 5 solid parabolic brick (CHEXA) elements — a = 10°



Boundary Conditions

• q displacement = 0 at all grid points

• Z displacement = 0 at all grid points along AA

• Grid points at same R and Z are constrained to have same z displacement

• One constraint set

Simply Supported "Solid" Annular Plate 239

Solution Type





Results

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTarget

Value (Hz)

NXNastranResult(lumpedmass)(Hz)

NXNastranResult(coupledmass) (Hz)


linear pyramid

parabolic brick

parabolic pyramid

19.66

18.58

18.57

19.90

18.45

21.30

18.61

19.90

18.58

21.50

240 Simply Supported "Solid" Annular Plate

Mode#

ReferenceValue(Hz)

Mesh NAFEMSTarget

Value (Hz)

NXNastranResult(lumpedmass)(Hz)

NXNastranResult(coupledmass) (Hz)


linear pyramid

parabolic brick

parabolic pyramid

146.4

140.4

138.8

147.0

135.9

140.0

140.5

148.0

140.3

143.0


linear pyramid

parabolic brick

parabolic pyramid

224.3

224.2

224.2

224.0

223.7

224.0

224.4

224.0

224.2

225.0


linear pyramid

parabolic brick

parabolic pyramid

386.7

374.0

361.8

383.0

351.2

359.0

372.1

390.0

371.9

376.0


linear pyramid

parabolic brick

parabolic pyramid

689.5

686.0

643.8

684.0

624.7

640.0

674.7

690.0

679.6

683.0

References


Cantilevered Solid Beam 241

11.7 Cantilevered Solid BeamThis test is a normal mode dynamic analysis of a cantilevered solid beam meshedusing solid elements. This document provides the input data and results forNAFEMS Selected Benchmarks for Natural Frequency Analysis, Test 72.


• Highly populated stiffness matrix


• nf072a.dat (parabolic bricks – conventional)

• nf072b.dat (parabolic bricks – unconventional)

• nf072c.dat (parabolic pyramids – conventional)

• nf072d.dat (parabolic pyramids – unconventional)

Units

SI

Material Properties

• E = 200E09 N/m2

• r = 8000 kg/m3

• n = 3

242 Cantilevered Solid Beam


Four tests:

• Test 1: solid parabolic brick (CHEXA) elements, conventional grid pointnumbering

• Test 2: solid parabolic pyramid (CPYRAM) elements (created by dividing eachbrick element into 6 pyramid elements), conventional grid point numbering

• Test 3: solid parabolic brick (CHEXA) elements, unconventional grid pointnumbering

• Test 4: solid parabolic pyramid (CPYRAM) elements (created by dividing eachbrick element into 6 pyramid elements), unconventional grid point numbering

Cantilevered Solid Beam 243

Boundary Conditions

• X = Y = Z = 0 at all grid points on X = 0 plane

• Y = 0 at grid points on Y = 1 m plane

Solution Type





Results

Mode # Mesh NAFEMSTarget Value

(Hz)



1 Test 1

Test 2

Test 3

Test 4

16.01

16.01

15.82

15.90

15.82

15.90

15.99

16.00

15.99

16.00

244 Cantilevered Solid Beam

Mode # Mesh NAFEMSTarget Value

(Hz)



2 Test 1

Test 2

Test 3

Test 4

87.23

87.23

83.18

84.30

83.18

84.30

87.09

87.00

87.09

87.00

3 Test 1

Test 2

Test 3

Test 4

126.0

126.0

125.5

126.0

125.5

126.0

126.0

126.0

126.0

126.0

4 Test 1

Test 2

Test 3

Test 4

209.6

209.6

193.5

198.0

193.5

198.0

209.1

209.0

209.1

209.0

5 Test 1

Test 2

Test 3

Test 4

351.1

351.1

310.1

323.0

310.1

323.0

349.9

350.0

349.9

350.0

6 Test 1

Test 2

Test 3

Test 4

375.8

375.8

364.2

367.0

364.2

367.0

375.8

375.0

375.8

375.0

References


Solid Cylinder in Pure Tension 245

11.8 Solid Cylinder in Pure TensionThis test is a linear statics analysis of a solid cylinder with tension-compression. Itprovides the input data and results for benchmark test SSLV01/89 from Guide devalidation des progiciels de calcul de structures.


• sslv01a.dat (Test 1)

• sslv01b.dat (Test 2)

• sslv01c.dat (Test 3)

• sslv01d.dat (Test 4)

• sslv01e.dat (Test 5)

• sslv01f.dat (Test 6)

246 Solid Cylinder in Pure Tension

Units

SI

Material Properties

• E = 2.0 x 1011 Pa

• n = 0.30



Test 1

• 155 parabolic tetrahedron (CTETRA) elements

• 342 grid points

Test 2

• 144 linear brick (CHEXA) elements & 48 linear solid wedge (CPENTA)elements

• 307 grid points

Test 3 (Results for this test will be provided in the NX Nastran 7 VerificationManual)

• 48 linear quadrilateral axisymmetric solid elements

• 65 grid points


• 96 linear triangular axisymmetric solid elements

• 65 grid points


• 18 parabolic quadrilateral axisymmetric solid elements

• 95 grid points

Test 6

• 864 linear pyramid (CPYRAM) elements created by dividing each brickelement in test 2 into 6 pyramid elements. 48 linear wedge (CPENTA)elements remain.


The meshes are shown in the following figure:


Boundary Conditions

• Uniaxial deformation of the cylinder section

• Set uniformly distributed force –F/A on the free end in the Z direction

• F/A = 100 MPa

The boundary conditions are shown in the following figure:

Solution Type



Results

linear statics

* axisymmetric data will be provided in version 7

Point GridPoint

DisplacementBenchValue

TestNumber

NX Nastran

A &C

6 u (m) 1.500E–3 1 1.500E–3

A &C

279 2 1.500E–3

A &C

1 3 *

A &C

4 4 *

A &C

1 5 *

A &C

279 6 1.500E–3

B 4 u (m) 1.500E–3 1 1.500E–3

B 307 2 1.500E–3

B 53 3 *

B 3 4 *

B 39 5 *

B 307 6 1.500E–3

D 37 u (m) 1.000E-3 1 1.000E–3

D 189 2 1.000E–3

D 5 3 *

D 25 4 *

D 7 5 *

D 189 6 1.000E–3

E 41 u (m) 0.5000E-3 1 0.500E–3

E 99 2 0.500E–3

E 9 3 *

E 29 4 *

E 13 5 *


Point GridPoint

DisplacementBenchValue

TestNumber

NX Nastran

E 99 6 0.500E–3

A &C

6 w (m) –0.1500E–3 1 –0.150E–3

A &C

279 2 –0.150E–3

A &C

1 3 *

A &C

4 4 *

A &C

1 5 *

A &C

279 6 –0.1500E–3

D 37 w (m) –0.1500E-3 1 –0.1500E–3

D 189 2 –0.1500E–3

D 5 3 *

D 25 4 *

D 7 5 *

D 189 6 –0.1500E–3

E 41 w (m) –0.1500E–3 1 –0.1500E–3

E 99 2 –0.1500E–3

E 9 3 *

E 29 4 *

E 13 5 *

E 99 6 –0.1500E–3

Post Processing

To view the results for Test 1 and Test 2, use coordinate system 2 (cylindrical). u isthe radial displacement and w is the axial displacement.

References

Societe Francaise des Mecaniciens. Guide de validation des progiciels de calcul destructures. Paris, Afnor Technique, 1990. Test No. SSLV01/89.

252 Internal Pressure on a Thick-Walled Spherical Container

11.9 Internal Pressure on a Thick-Walled SphericalContainer

This test is a linear statics analysis of a thick sphere with internal pressure. Itprovides the input data and results for benchmark test SSLV03/89 from Guide devalidation des progiciels de calcul de structures.


Input Files







Units

SI

Internal Pressure on a Thick-Walled Spherical Container 253

Material Properties

• E = 2 x 105 Pa

• n = 0.3


Test 1

• 1600 linear brick (CHEXA) elements & linear solid wedge (CPENTA) elements

• 1898 grid points

Test 2

• 200 parabolic brick (CHEXA) elements & 50 solid wedge (CPENTA) elements




• 451 grid points




Test 5

• Linear pyramid (CPYRAM) elements created by dividing each brick element intest 1 into 6 pyramid elements. Wedge (CPENTA) elements remain.

Test 6

• Parabolic pyramid (CPYRAM) elements created by dividing each brick elementin test 2 into 6 pyramid elements. Wedge (CPENTA) elements remain.


The meshes from these tests are shown in the following figure:


Boundary Conditions

• The equivalent of the center of the sphere being fixed is modeled via symmetricboundary conditions.

• Uniform radial pressure = 100 MPa.


Solution Type



Results


Point GridPoint

DisplacementStress

BenchValue

TestNumber

NX Nastran

r=1 m 1 srr (MPa) –100.0 1 –90.15

1 2 –97.29

451 3 *

451 4 *

1 5 –90.84

1 6 -103.8

1 sq (MPa) 71.43 1 72.09

1 2 77.23

451 3 *

451 4 *

1 5 72.06

1 6 73.30

1 u (m) 0.4000E–3 1 0.4000E–3

1 2 0.4000E–3

451 3 *

451 4 *

1 5 0.3991E–3

1 6 0.4006E–3


Point GridPoint

DisplacementStress

BenchValue

TestNumber

NX Nastran

r=2 m 1826 srr (MPa) 0 1 –0.0280

2221 2 0.2240

411 3 *

411 4 *

1826 5 –0.2530

2221 6 –0.5259

1826 sq (MPa) 21.43 1 21.18

2221 2 21.18

411 3 *

411 4 *

1826 5 21.40

2221 6 21.74

1826 u (m) 1.500E–4 1 1.500E–4

2221 2 1.500E–4

411 3 *

411 4 *

1826 5 1.506E–4

2221 6 1.499E–4

All stress results are averaged. Use the spherical coordinate system for the stressresults.

References


258 Internal Pressure on a Thick-Walled Infinite Cylinder

11.10 Internal Pressure on a Thick-Walled Infinite CylinderThis test is a linear statics analysis of a thick cylinder with internal pressure. Itprovides the input data and results for benchmark test SSLV04/89 from Guide devalidation des progiciels de calcul de structures.


Input Files







Units

SI

Internal Pressure on a Thick-Walled Infinite Cylinder 259

Material Properties

• E = 2 x 105 mPa

• n = 0.3


Test 1

• 400 linear brick (CHEXA) elements

• 902 grid points

Test 2

• 240 parabolic brick (CHEXA) elements


Test 3


• 656 grid points

Test 4



Test 5

• Linear pyramid (CPYRAM) elements created by dividing each brick element intest 1 into 6 pyramid elements.

Test 6

• Parabolic pyramid (CPYRAM) elements created by dividing each brick elementin test 2 into 6 pyramid elements.


The brick meshes are shown in the following figure:


Boundary Conditions

• Unlimited cylinder

• Internal pressure p = 60 MPa


Solution Type


Results

All results are averaged.

TestCase

GridPoint

Displacement /Stress

BenchValue

NX Nastran

sslv04a 411 sr –60.00(MPa)

–57.00

sslv04b 977 –60.00

sslv04c 616 *

sslv04d 1831 *

sslv04e 411 –57.30

sslv04f 977 –60.74

sslv04a 411 sq 100.0(MPa)

99.70

sslv04b 977 102.0


TestCase

GridPoint


BenchValue

NX Nastran

sslv04c 616 *

sslv04d 1831 *

sslv04e 411 99.68

sslv04f 977 100.9

sslv04a 411 tmax 80.00(MPa)

79.34

sslv04b 977 81.00

sslv04c 616 *

sslv04d 1831 *

sslv04e 411 80.82

sslv04f 977 80.82

sslv04a 411 ur 59.00E–6(m)

59.00E–6

sslv04b 977 59.00E–6

sslv04c 616 *

sslv04d 1831 *

sslv04e 411 58.85E–6

sslv04f 977 59.00E–6

sslv04a 451 sr 0 (MPa) –0.006500

sslv04b –0.04480

sslv04c *

sslv04d *

sslv04e –0.1563

sslv04f –0.1900

sslv04a sq 40.00(MPa)

39.66

sslv04b 40.39

sslv04c *

sslv04d *

sslv04e 39.84


TestCase

GridPoint


BenchValue

NX Nastran

sslv04f 40.16

sslv04a tmax 20.00(MPa)

20.08

sslv04b 20.17

sslv04c 20.07

sslv04d 19.99

sslv04e 20.10

sslv04f 20.17

sslv04a ur 40.00E–6(m)

40.00E–6

sslv04b 40.00E–6

sslv04c *

sslv04d *

sslv04e 39.93E–6

sslv04f 40.00E–6

References


264 Prismatic Rod in Pure Bending

11.11 Prismatic Rod in Pure BendingThis test is a linear statics analysis of a solid rod with bending. It provides theinput data and results for benchmark test SSLV08/89 from Guide de validationdes progiciels de calcul de structures.


Input Files







Prismatic Rod in Pure Bending 265

Units

SI

Material Properties

• E = 2 x 105 MPa

• n = 0.3


Finite Element ModelingTest 1

• 198 linear solid tetrahedral (CTETRA) elements

• 76 grid points

Test 2

• 198 parabolic solid tetrahedral (CTETRA) elements

• 409 grid points

Test 3


• 117 grid points

Test 4 — Mapped meshing

• 48 parabolic brick (CHEXA) elements

• 381 grid points

Test 5

• 288 linear pyramid (CPYRAM) elements created by dividing each brickelement in test 3 into 6 pyramid elements.

Test 6

• 288 parabolic pyramid (CPYRAM) elements created by dividing each brickelement in test 4 into 6 pyramid elements.



Boundary Conditions

• Clamp Point B.

• Other points of B section: Set Z-displacement to 0. NOTE: In these tests somegrid points of section B are also restrained in the x direction about the x-axisat the free end of the rod.

• Set moment Mx equal to (4/3)E+7 N.m


Solution Type



ResultsTest # Point Grid

PointDisplacementStress

Bench Value NX Nastran

1 F or G 5 szz –10.00E6 (Pa) –4.268E6

2 5 –10.03E6

3 75 –10.00E6

4 245 –9.995E6

5 75 –7.929E6

6 245 –9.992E6

1 A 26 uA 4.000E–4 (m) 2.964E–4

2 90 4.000E–4

3 77 4.000E–4

4 251 4.000E–4

5 77 3.443E–4

6 251 4.000E–4

1 H 19 wB 2.000E–4 (m) 2.000E–4

2 40 2.000E–4

3 76 2.000E–4

4 249 2.000E–4

5 76 1.721E–4

6 249 2.000E–4

1 F or G 5 vF = -vG 0.1500E-4 (m) 0.07450E–4

2 5 0.1508E–4

3 75 0.1500E–4

4 245 0.1503E–4

5 75 0.1005E–4

6 245 0.1503E–4

1 D orE

8 vD = -vE -0.1500E-4 (m) –6.262E–4

2 8 –0.1505E–4

3 73 –0.1500E–4

4 241 –0.1503E–4

5 73 –0.1005E–4

6 241 –0.1503E–4


References


270 Thick Plate Clamped at Edges

11.12 Thick Plate Clamped at EdgesThis test is a linear statics analysis of a thick plate with pressure and transversebending. It provides the input data and results for benchmark test SSLV09/89 fromGuide de validation des progiciels de calcul de structures.


Input Files




Units

SI

Material Properties

• E = 2.1 x 1011 Pa

• n = 0.3

Thick Plate Clamped at Edges 271


Test 1

• 25 parabolic linear brick (CHEXA) elements

• 228 grid points

• l =10, 20, 50, 75, 100

Test 2

• 25 linear quadrilateral thin shell (CQUAD4) elements

• 36 grid points

• l =10, 20, 50, 75, 100

Test 3

• 150 linear pyramid solid (CPYRAM) elements created by dividing each brickelement in test 1 into 6 pyramid elements

Test 2 is done using CQUAD4 elements with the thicknesses specified in thephysical property table.



Boundary Conditions

• AB and AD sides: clamped

• BC and DC sides: symmetry

• Load case 1:

Pressure p = 1E06 Pascals in –Z direction

• Load case 2: Point C

Grid Point force F = 1E06 N in –Z direction


Thick Plate Clamped at Edges 273

Solution Type

SOL 101 Linear statics

Results

Test Case 1 (z displacement at location C)

PartName

Load Case Grid Point Analytical Reference FEM NX Nastran

10 Pressure 242 –0.6552E-4 –0.7620E–4 –0.7379E–4

Force 242 –0.2915E-3 –0.4300E–3 –0.3684E–3

20 Pressure 1242 –0.5242E-3 –0.5383E–3 –0.5266E–3

Force 1242 –0.2332E–2 –0.2535E–2 –0.2456E–2

50 Pressure 2242 –0.8190E–2 –0.8029E–2 –0.7935E–2

Force 2242 –0.3643E–1 –0.3574E–1 –0.3602E–1

75 Pressure 3242 –0.2764E–1 –0.2690E–1 –0.2666E-1

Force 3242 –0.1230 –0.1184 –0.1206

100 Pressure 4242 –0.6552E–1 –0.6339E–1 –0.6305E–1

Force 4242 –0.2915 –0.2779 –0.2849


PartName


10 Pressure 1 –0.6552E–4 –0.7866E–4 –0.8131E–4

Force 1 –0.2915E–3 –0.4109E–3 –0.4050E–3

20 Pressure 36 –0.5242E–3 –0.5557E–3 –0.5775E–3

Force 36 –0.2332E–2 –0.2595E–2 –0.2668E–2

50 Pressure 36 –0.8190E–2 –0.8348E–2 –0.8669E–2

Force 36 –0.3643E–1 –0.3745E–1 –0.3878E–1

75 Pressure 36 –0.2764E–1 –0.2805E–1 –0.2906E–1

Force 36 –0.1230 –0.1253 –0.1292

100 Pressure 36 –0.6552E–1 –0.6639E–1 –0.6864E–1

Force 36 –0.2915 -0.2958 –0.3042



PartName


10 Pressure 242 –0.6552E-4 –0.7620E–4 –0.7491E–4

Force 242 –0.2915E-3 –0.4300E–3 –0.3736E–3

20 Pressure 1242 –0.5242E-3 –0.5383E–3 –0.5342E–3

Force 1242 –0.2332E–2 –0.2535E–2 –0.2458E–2

50 Pressure 2242 –0.8190E–2 –0.8029E–2 –0.7875E–2

Force 2242 –0.3643E–1 –0.3574E–1 –0.3470E–1

75 Pressure 3242 –0.2764E–1 –0.2690E–1 –0.2605E-1

Force 3242 –0.1230 –0.1184 –0.1135

100 Pressure 4242 –0.6552E–1 –0.6339E–1 –0.6068E–1

Force 4242 –0.2915 –0.2779 –0.2627

References


Hollow Sphere - Fixed Temperatures, Convection 275

11.13 Hollow Sphere - Fixed Temperatures, ConvectionThis test is a steady-state heat transfer analysis of a 3D sphere with fixedtemperatures and convection. It provides the input data and results for benchmarktest TPLV02/89 from "Guide de validation des progiciels de calcul de structures."

• Ri = 0.30 m

• Re = 0.35 m


htpv02.dat (CHEXA and CPENTA)

htpv02p.dat (CPYRAM and CPENTA)

UnitsSI

Material Properties• l = 1 W/m °C

Finite Element ModelingTest 1: Brick and wedge element test

• 500 linear brick (CHEXA) and linear wedge (CPENTA) elements

• 766 grid points

276 Hollow Sphere - Fixed Temperatures, Convection

The test is executed on 1/8 mapped meshed sphere.

The mesh is shown in the following figure:

Test 2: Pyramid and wedge element test

• Linear pyramid (CPYRAM) elements created by dividing each brick element intest 1 into 6 pyramid elements. Linear wedge (CPENTA) elements remain.

Boundary Conditions• Convection on internal surface

hi = 30 W/m2 °C

Ti = 100 °C

• Set external surface temperature Te to 20 °C

The load sets are shown in the following figure:

Hollow Sphere - Fixed Temperatures, Convection 277

Solution Type

SOL 153 — Steady State Heat Transfer

Results

Temperature results (°C)

Test Radius r (m) Bench Value NX Nastran

Test 1 0.3000 65.00 64.88

Test 2 0.3000 65.00 64.86

Test 1 0.3100 54.84 54.75

Test 2 0.3100 54.84 54.72

Test 1 0.3200 45.31 45.25

Test 2 0.3200 45.31 45.23

Test 1 0.3300 36.36 36.33

Test 2 0.3300 36.36 36.30

Test 1 0.3400 27.94 27.92

Test 2 0.3400 27.94 27.91

Test 1 0.3500 20.00 20.00

Test 2 0.3500 20.00 20.00

Flux results (W/m2): (X-direction)


Test 1 0.3000 1050. 1013.

278 Hollow Sphere - Fixed Temperatures, Convection


Test 2 0.3000 1050. 1013.

Test 1 0.3100 983.4 981.4

Test 2 0.3100 983.4 981.6

Test 1 0.3200 922.9 921.2

Test 2 0.3200 922.9 921.3

Test 1 0.3300 867.5 866.3

Test 2 0.3300 867.5 866.3

Test 1 0.3400 817.5 816.3

Test 2 0.3400 817.5 816.1

Test 1 0.3500 771.4 792.4

Test 2 0.3500 771.4 792.1

References

Societe Francaise des Mecaniciens. Guide de validation des progiciels de calcul destructures. Paris, Afnor Technique, 1990. Test No.TPLV02/89.

Hollow Sphere with Two Materials - Convection 279

11.14 Hollow Sphere with Two Materials - ConvectionThis test is a steady-state heat transfer analysis of a 3D sphere with two materialsand convection. It provides the input data and results for benchmark testTPLV04/89 from "Guide de validation des progiciels de calcul de structures."

• Ri = 0.30 m

• Rm = 0.35 m

• Re = 0.37 m


htpv04a.dat (CHEXA & CPENTA) elements

htpv04b.dat (CTETRA) elements

htpv04c.dat (CTRIAX6) elements

htpv04p.dat (CPYRAM & CPENTA) elements

Units

SI

Material Properties

• Material 1: l1 = 40.0 W/m °C

• Material 2: l2 = 20.0 W/m °C

280 Hollow Sphere with Two Materials - Convection


• Test 1 - 700 solid linear brick (CHEXA) & solid linear wedge (CPENTA)elements

• Test 2 - 2192 solid parabolic tetrahedron (CTETRA) elements

• Test 3 - 8 axisymmetric parabolic elements (Results for this test will beprovided in the NX Nastran 7 Verification Manual)

• Test 4- Linear pyramid (CPYRAM) elements created by dividing each brickelement in test 1 into 6 pyramid elements. Linear wedge (CPENTA) elementsremain.

The test is executed on a 1/8 meshed sphere


The meshes are shown in the following figure:

Boundary Conditions

• Convection on internal surface:

hi = 150.0 W/m2 °C

Ti = 70 °C

• Convection on external surface:

he = 200.0 W/m2 °C

282 Hollow Sphere with Two Materials - Convection

Te = –9 °C


Solution Type


Results

Temperature Results


TemperatureFlux (°C)

BenchValue

CHEXA&CPENTA

CTETRA Axisymmetric CPYRAM &CPENTA

Ti 25.06 N1 25.02 N1925.06

* N1 23.66

Tm 17.84 N55617.84

N9 17.84 * N556 16.26

Te 13.16 N77813.18

N5 13.15 * N778 13.85

i(W/m2)

6741. N1 6487. N195865.

* N1 6683.

m(W/m2)

4952. N5564931.

N9 4765. * N556 5080.


TemperatureFlux (°C)

BenchValue

CHEXA&CPENTA

CTETRA Axisymmetric CPYRAM &CPENTA

e(W/m2)

4431. N7784531.

N5 4551. * N778 4669.

f = f * 4 * π * R2

So: f = 4931.20 * 4 * π * 0.352 = 7590.00 W

Flux is in the x direction

References


284 Orthotropic Cube

11.15 Orthotropic CubeThis test is a steady-state heat transfer analysis of a 3D cube with convection andflux density. It provides the input data and results for benchmark test TPLV07/89from "Guide de validation des progiciels de calcul de structures."


htpv07.dat (CHEXA)

htpv07p.dat (CPYRAM)

Units

SI

Material Properties

• lx = 1.00 W/m °C

• ly = 0.75 W/m °C

• lz = 0.50 W/m °C


Test 1: Brick element test

Orthotropic Cube 285


• 729 grid points

The mesh is shown in the following figure:

Test 2: Pyramid element test

• 3072 linear pyramid (CPYRAM) elements created by dividing each brickelement in test 1 into 6 pyramid elements.

Boundary Conditions

• Flux density y = 60 W/m2 for face y = –0.1 (Entry)

• Flux density y = –60 W/m2 for face y = 0.1 (Exit)

• Flux density z = 30 W/m2 for face z = –0.1 (Entry)

• Flux density z = –30 W/m2 for face z = 0.1 (Exit)

• Convection on the faces X = –0.1 and x = 0.1:

–h = 15.0 W/m2 °C

• Linear variation of the external temperatures:

–Te = 30 – 80y – 60z on the face x = –0.1

–Te = 15 – 80y – 60z on the face x = 0.1

286 Orthotropic Cube


Solution Type


Results

Temperature results (°C)

Test Point BenchValue

NX Nastran

Test1 A 35.00 34.70

Test2 A 35.00 34.70

Test1 B 26.00 25.70

Test2 B 26.00 25.70

Test1 C 10.00 10.30

Test2 C 10.00 10.30

Test1 D 19.00 19.30

Test2 D 19.00 19.30

Test1 S 30.50 30.40

Orthotropic Cube 287

Test Point BenchValue

NX Nastran

Test2 S 30.50 30.40

Test1 F 18.00 18.00

Test2 F 18.00 18.00

Test1 M 14.50 14.60

Test2 M 14.50 17.70

Test1 H 27.00 27.00

Test2 H 27.00 27.00

Test1 N 29.00 29.00

Test2 N 29.00 29.00

Test1 P 20.00 20.00

Test2 P 20.00 20.00

Test1 J 4.000 4.600

Test2 J 4.000 4.590

Test1 I 13.00 13.60

Test2 I 13.00 13.60

Test1 E 16.50 16.60

Test2 E 16.50 16.60

Test1 R 41.00 40.40

Test2 R 41.00 40.40

Test1 Q 32.00 31.40

Test2 Q 32.00 31.40

Test1 K 16.00 16.00

Test2 K 16.00 16.00

Test1 L 25.00 25.00

Test2 L 25.00 25.00

Test1 G 28.50 28.40

Test2 G 28.50 28.40

References


Chapter

12Upward Compatibility

12.1 Updated Modules

BDRYINFO

Generate the geometry and connectivity information for an external superelementdefinition based on the ASETi and QSETi Bulk Data entries and requested by theEXTSEOUT Case Control command.

Updated Format:

BDRYINFO CASECC,GEOM1,GEOM2,BGPDT,GPDT,USET/GEOM1EX,GEOM2EX,GEOM4EX,CASEX/DMIGSFIX $

New Input Data Blocks:

GPDT Grid point definition table

New Output Data Block:

CASEX Table of Case Control command images modified with additionaloutput requests due to PLOTELs.

New Parameter:

DMIGSFIX Input-character-default=” ” (default=eight blank spaces).Suffix for DMIG matrices.

290 Updated Modules

COMBOUT

Combine output data blocks.

Format:

COMBOUT OUT1,OUT2/OUTC/S,N,CFLAG

Updated Remark 1:

1. OUT1 and OUT2 must be compatible. This means the data must be the same(e.g. both are displacements) and the numerical type must be the same(e.g. both are real or both are complex). If both are complex, both must bereal/imaginary or magnitude/phase.

Updated Modules 291

EMA

Assembles global g-set size matrix from elemental matrices

Updated Format:

EMA GPECT,XDICT,XELM,BGPDT,SIL,CSTM,XDICTP,XELMP,X4ELM,X4DICT/XGG,UNUSED2/NOK4GG/WTMASS $

New Input Data Blocks:

X4ELM Table of element matrices for structural damping

X4DICT Element matrix dictionary table for structural damping

292 Updated Modules

EMG

Computes elemental matrices for stiffness, differential stiffness, mass, damping,heat conduction, or heat capacity.

Updated Format:

EMG EST,CSTM,MPT,DIT,UNUSED5,UG,ETT,EDT,DEQATN,DEQIND,BGPDT,GPSNT,ECTA,EPTA,EHTA,DITID,EBOLT/KELM,KDICT,MELM,MDICT,BELM,BDICT/S,N,NOKGG/S,N,NOMGG/S,N,NOBGG/S,N,NOK4GG/S,N,NONLHT/COUPMASS/TEMPSID/DEFRMSID/PENFAC/IGAPS/LUMPD/LUMPM/MATCPX/KDGEN/TABS/SIGMA/K6ROT/LANGLE/NOBKGG/ALTSHAPE/PEXIST/FREQTYP/FREQVAL/FREQWA/UNSYMF/S,N,BADMESH/DMGCHK/BOLTFACT/REDMAS/TORSIN/SHLDAMP/SHLDMP/BSHDMP $

New Parameters:

DMGCHK Input-logical-default=TRUE. Element geometry check flag.It works in conjunction with the GEOMCHECK exec controlstatement. If both the GEOMCHECK statement (via theGCHECK logical variable in /ERRMSG/ ... WORD6) andDMGCHK=TRUE, then optional checks are performed.

BOLTFACT Input-real-default=1.0E+07. Factor used to reduce the boltstiffness during the first phase of a bolt preload analysis.

REDMAS Input-logical-default=TRUE. Determines if reduced massintegration occurs. Only for tetrahedral elements and whenmass is for acceleration loading.

TORSIN Input-integer-default=0. Determines if torsional mass momentof inertia is included for CROD and CBAR.TORSIN=0 Torsional mass moment of inertia is not included forCROD and CBARTORSIN=1 It is included for CROD and CBARTORSIN=2 Included only for CBAR.TORSIN=3 Included only for CROD.

Updated Modules 293

SHLDAMP Input-character-default=‘SAME’ Determines the strategy forshell structural damping.= SAME The structural damping coefficient (GE) defined ona PSHELL MID1 material will be used by all MIDi for thatPSHELL, and SHLDMP is assigned a value of 0 (see SHLDMPbelow).= DIFF The structural damping coefficient (GE) defined on eachPSHELL MIDi will be used. SHLDMP is assigned a value of 1(see SHLDMP below). Otherwise, SHLDMP=0.

SHLDMP Input/output-integer-default=0. Structural damping flag forPSHELL property entries.

First call to EMG:

Input FromSHLDAMP

OutputValue Definition

0 0All elements are processednormally. Just one call to EMG.

1 -1

All elements are processednormally, except the value of GEon the KDICT datablock for theshell element stiffness is assigneda value of 0.0, and EMG is called asecond time for element dampingmatrices.

Second call to EMG when SHLDMP=-1:

InputValue


–1 1

For shell elements, the element stiffnessis multiplied by the corresponding GEi,and GE on the KDICT datablock isassigned a value of 1.0.

294 Updated Modules

BSHDMP Input/output-integer-default=0. Structural damping flag forPBUSH and PBUSHT property entries.

First call to EMG:

Input FromBSHDAMP onTA1 module


0 0All elements are processednormally. Just one call to EMG.

1 -1

All elements are processednormally, except the value of GEon the KDICT datablock for thebush element stiffness is assigneda value of 0.0, and EMG is called asecond time for element dampingmatrices.

Second call to EMG when BSHDMP=-1:

InputValue


–1 1

For bush elements, the element stiffness ismultiplied by the corresponding GEi, andGE on the KDICT datablock is assigned avalue of 1.0.

Updated Modules 295

EXTSEIDS

Generate grid and element ID lists for an external partitioned superelement.

Updated Format:

EXTSEIDS TUG1,TQG1,TQMG1,TGPF,TES1,TEE1,TEF1/SEGRD,SEELM

New Input Data Block:

TGPF Table of grid point force balance grids for external partitionedsuperelement.

296 Updated Modules

FOCOEL

Form contact elements

Updated Format:

FOCOEL CASECC,BGPDT,CSTM,GEOM2,EST,MPT,CONTACT,SIL/CNELMS,GPECTC/S,N,NSKIP/S,N,OPTION/S,N,NLHEAT/S,N,CNTSET/S,N,NCELS/S,N,MAXS/S,N,MAXF/S,N,CNTS/S,N,AITK/S,N,MPER/S,N,RESET/S,N,FRICTM/S,N,TARPEN/S,N,ADAPT/S,N,SCALMT $

New Parameters:

FRICTM Output-real. Maximum coefficient of friction.

TARPEN Output-real. Target penetration. TARPEN is the product ofthe BCTPARM parameter PENETFAC and the effective depthcalculated by the solver. It is used in the calculation of a scalefactor that adaptively scales the contact stiffness matrix whenPENADAPT is selected in the BCTPARM bulk entry.

ADAPT Output-integer.=0 adaptive stiffness option is not selected in the BCTPARM bulkentry.>0 adaptive stiffness option is selected in the BCTPARM bulk entry.

SCALMT Output-integer. Maximum number of outer loop iterations to allowscaling of contact stiffness matrix.=3 for shell models=MAXO for solid models

Updated Modules 297

FOELCF

Form contact forces

Updated Format:

FOELCF CNELM,ECSTAT,ECDISP,ECDISO,ELAMDA,DLAMDA,XYDISP/DLAMUP,CONFOR,TLAMCK,XYDISU/S,N,NROW/S,N,CONV/S,N,CITO/S,N,SCALE/S,N,KCSCALE/S,N,TARPEN/S,N,CITI $

New Parameters:

SCALE Input-real. Scale factor for normal and tangential penalty factors.

KCSCALE Output-real. Scale factor used for contact stiffness matrix. It iscomputed based on the ration of average penetrations in the modeland target penetration (TARPEN).

TARPEN Output-real. Target penetration. TARPEN is the product ofthe BCTPARM parameter PENETFAC and the effective depthcalculated by the solver. It is used in the calculation of a scalefactor that adaptively scales the contact stiffness matrix whenPENADAPT is selected in the BCTPARM bulk entry.

CITI Input-integer. Contact inner (force) loop counter.

298 Updated Modules

GKAM

Assembles modal mass, damping and stiffness matrices

Updated Format:

GKAM USETD,PHA,MI,LAMA,DIT,M2DD,B2DD,K2DD,CASECC,EMVD/MHH,BHH,KHH,PHDH,ZETA/NOUE/LMODES/LFREQ/HFREQ/UNUSED5/UNUSED6/UNUSED7/S,N,NONCUP/S,N,FMODE/KDAMP/FLUID/UNUSED12 $


EMVD Diagonal matrix of equivalent modal viscous damping. SeeRemark 8.

New Remark:

1. If EMVD exists, ZETA will contain EMVD values; otherwise ZETA valueswill be derived.

Updated Modules 299

GPFDR

Computes grid point forces and element strain energy

Updated Format:

GPFDR

Updated Output Data Blocks:

ONRGY1 Table of element strain energies and energy densities in SORT1format.

OGPFB1 Table of grid point forces in SORT1 format.

OEKE1 Elemental kinetic energy in SORT1 format.

OEDE1 Elemental energy loss in SORT1 format.

New Parameters:

NOSORT2 Output-integer-default=-1. SORT2 format flag for OGPFB1datablock. Set to 1 if SORT2 format is requested; –1 otherwise.

300 Updated Modules

MATMOD

Matrix modification

Transforms matrix or table data blocks according to one of many options intooutput matrix or table data blocks.

General Format:

MATMOD I1,I2,I3,I4,I5,I6,I7,I8,I9,I10,I11,I12,I13/O1,O2/P1/P2/P3/P4/P5/P6/P7/P8/P9/P10/P11/P12/p13/p14/p15 $

Updated Option P1 = 16

Put matrix into MATPOOL format, optional DMIG punched output.

Updated Format:

MATMOD I1,I2,,,,,,,,,,,/O1,/16/PNDMIG/USENAM/TYPOUT////////CCHAR/MATNAM $

New Parameters

USENAM Input-integer-default=0. If USENAM≠0 and PNDMIG≠0, I1 isprinted using the name defined in MATNAM.

MATNAM Input-character-default=blank. Matrix name to use for I1.Only valid when USENAM≠0 and PNDMIG≠0.

Updated Example:

Output KGG and PG matrices in MATPOOL formatted table and punch to DMIGBulk Data entries (MATGEN Option 9 is being used to resequence them frominternal to external sort).

MATGEN EQEXIN/INTEXT/9/0/LUSET $MPYAD INTEXT,KGG,/KGGE/1 $MPYAD KGGE,INTEXT,/KGGEXT $MATMOD KGGEXT,EQEXIN,,,,,,,,,,,/MATPOOL1,/16/1 $MPYAD INTEXT,PG,/PGEXT/1 $MATMOD PGEXT,EQEXIN,,,,,,,,,,,/MATPOOL2,/16/1 $MATMOD KGGEXT,EQEXIN,,,,,,,,,,,/MATPOOL1,/16/1/1//////////KNAME $

Updated Modules 301

New Option P1 = 29

Make output requests consistent for superelement combined output.

Format:

MATMOD CASECC,,,,,,,,,,,,/XCASECC,/29 $

Input Data Blocks:

CASECC Table of Case Control command images

Output Data Blocks:

XCASECC Modified table of Case Control command images

Remarks:

This only makes sense with PARAM,SECOMB,YES.

302 Updated Modules

PARAML

Sets parameters from a data block

Format:

PARAML DB/DBNAME/P1/S,N,P2/S,N,P3/S,N,P4/S,N,P5/S,N,P6/S,N,SET1/S,N,F1/S,N,SET2/S,N,F2/S,N,SET3/S,N,F3/S,N,SET4/S,N,F4/S,N,SET5/S,N,F5/S,N,SET6/S,N,F6/S,N,SET7/S,N,F7/S,N,SET8/S,N,F8/S,N,SET9/S,N,F9/S,N,SET10/S,N,F10/S,N,SET11/S,N,F11/S,N,SET12/S,N,F12/S,N,P7/S,N,P8/S,N,P9 $

Updated Option P1 = ‘DMI’

Extract an element from a matrix.

Format:

PARAML MAT//’DMI’/ICOL/IROW/S,N,REAL/S,N,NROW/S,N,IMAG/////////////////////////S,N,DFLAG/S,N,DREAL/S,N,DIMAG $

New Parameters:

DFLAG Output-integer.

=1, single precision

=2, double precision.

DREAL Output-real(double precision). Real part of matrix element.

DIMAG Output-real(double precision). Imaginary part of matrix element,if element is complex.

Updated Remarks:

If IROW is greater than the number of rows in the matrix, NROW is set to thenumber of rows, and REAL, IMAG, DREAL and DIMAG are set to zero.

Updated Modules 303

RMAXMIN

Searches result tables during SOL 112.

Searches stress, force and displacement tables during SOL 112 for extreme values.

Updated Format:

RMAXMIN OUGV1,OEF1,OES1/OUGV1MX,OEF1MX,OES1MX/IFABS,IAPPN,IDIAG,RMXTRAN,NPAVG,START,END $

New Parameters:

RMXTRAN Input parameter to provide an alternate and overiding request ofthe bulk data parameter RMXTRAN.

NPAVG Input parameter to declare the maximum number of peaks toaverage.

START Input parameter to set the start time of an interval in the totaltime domain.

END Input parameter to set the end time of an interval in the totaltime domain.

304 Updated Modules

ROTCDA

Generates output data for Campbell’s diagram from rotor dynamic analysis.

Data is written to OP2 or punch file. Also, generates a comma-separated ASCII filethat can be imported into Microsoft Excel to display Campbell’s diagrams.

Updated Format:

ROTCDA OMGMTDR,CLAMTRDR,CLAMTIDR,WHRDIR,SLAMTRDR,SLAMTIDR,SWHRDIR,RSPEEDT/CDDATA/ROTGPF/ROTCSV/IREFS/IRSPEED/IRFREQ/ROTPRNT $


RSPEEDT Rotational speed factors.

Updated Modules 305

SOLVIT

Iterative solver

Solves the matrix equation [A] [X] = ± [B] for [X] using a preconditioned conjugategradient method.

Updated format for element based solution:

SOLVIT KELM,PG,KDICT,SIL,ECT,BGPDT,CSTM,EDT,CASECC,USETB,RG,MPT,YGB,SLT,MDICT,MELM,EPT,,CNELM,ELCNST,ELCTST/UGV,QG,,/V,Y,ISIGN/V,Y,IOPT/S,N,ITSEPS/V,Y,ITSMAX/V,Y,IPAD/V,Y,IEXT//NSKIP/V,Y,IMSGFL/V,Y,IDEBUG/V,Y,ITSERR/WTMASS $

New Parameters:

ITSERR Output-integer-default = 0. Iterative solver return code.

WTMASS Input,Real – Weight to mass factor

306 Updated Modules

TA1

Combines all of the element data (geometry, connection, and properties) into atable(s) convenient for generation of the element matrices (stiffness, mass, and soon) and output quantities (stress, force, and so on).

Updated Format:

TA1

MPT,ECT,EPT,BGPDT,SIL,ETT,CSTM,DIT,ECTA,EHT/EST,ESTNL,GEI,GPECT,ESTL,VGFD,DITID,NFDICT/LUSET/S,N,NOESTL/S,N,NOSIMP/NOSUP/S,N,NOGENL/SEID/LGDISP/NLAYERS/S,N,FREQDEP/BSHDAMP/S,N,BSHDMP/NSMID $

New Parameters:

BSHDAMP Input-character-default=‘DIFF’. Determines if thePBUSH/PBUSHT bulk entry fields GE2-GE6 andTGEID2-TGEID6 are considered.= SAME The fields GE2-GE6/TGEID2-TGEID6 are ignored, onlythe fields GE1/TGEID1 are considered and BSHDMP on the EMGmodule is assigned a value of 0.= DIFF The fields GE2-GE6/TGEID2-TGEID6 are considered. Ifall PBUSH/PBUSHT GE2-GE6/TGEID2-TGEID6 fields are blank,BSHDMP on the EMG module is assigned a value of 0. Otherwise,BSHDMP=1.

BSHDMP Output-integer-default=0. BUSH structural damping strategy forEMG module.See BSHDAMP above and BSHDMP on EMG module for details.

NSMSID Input-integer-default=0. Set identification number from the NSMCase Control command.

Updated Modules 307

VEC

Creates partitioning vector based on USET

Creates a partitioning vector based on degree-of-freedom sets. The vector can beused by the MERGE and PARTN modules.

Format 1 (Partitioning Vector):

VEC USET,/CP/MAJOR/SET1/SET2/UNUSED4/SET3 $

Format 2 (DOF Vector):

VEC USET,BGPDT/DOFVEC/MAJOR//SET2 $


BGPDT Basic grid point definition table.

New Output Data Block:

DOFVEC Dof vector

Updated Remarks:

The supersets formed by the union of other sets have the following definitions:

308 Updated Modules

1. For format 1, if MAJOR = ‘BITID‘, SET1 and SET2 are ignored andthe set name specified for SET3 corresponds to the zeros in CP andMAJOR corresponds to G or P for USET and USETD, respectively. Thosedegrees-of-freedom not in SET3 correspond to ones in CP.

2. For format 1, if SET1 (or SET2, but not both) is set to ‘COMP’(or left blank),SET1 (or SET2) is assumed to be the complement of SET2 (or SET1).

3. For format 2, MAJOR corresponds to the size of USET and SET2 correspondsto the required set within USET. DOFVEC will contain two columns of realvalues for each dof in the SET2 set; column 1 will contain the grid numbersand column2 will contain the corresponding direction numbers. DOFVEC willbe the length of the SET2 set. Scalar dof are ignored.

4. The set names MAJOR, SET1, and SET2, can specify a combination of setnames separated by a plus (+) or minus (-) character. The plus (+) characterindicates a union and the minus (-) character an exclusion. For example,‘a-b+m’indicates the a-set without the b-set. This resultant set is then joinedwith the m-set.

5. USET cannot be purged.

Updated Modules 309

Updated Examples:

1. To partition [Kff] into a- and o-set based matrices, use

VEC USET,/V/‘F‘/‘O’$PARTN KFF,V,/KOO,KAO,KOA,KAA $

Note that the same thing can be done in one step by:

UPARTN USET,KFF/KOO,KAO,KOA,KAA/‘F‘/‘O’$

2. Example 1 can be accomplished by:

VEC USET,/V/‘F‘/‘O’$

or

VEC USET,/V/‘F‘/‘A’$

3. Example 1 can also be accomplished by:

VEC USET,/V/‘BITID‘////‘A’$

4. To generate a DOFVEC of the f-set degrees-of-freedom contained within USET:

VEC USET,BGPDT/DOFVEC/’G’//’F’ $

310 New Modules

12.2 New Modules

CNTITER

Perform surface to surface contact using the element iterative solver.

Format:

CNTITER KELM,PG1,KDICT,SILS,ECT,BGPDT,CSTM,EDT,CASECC,USET,RG,MPT,YG,SLT,MDICT,MELM,EPT,CNELM,ELCNST,ELCTST/UGV1,QG1,OQGCF1,OBC1,CONFON,ELTRCT1,OSPDSI1,OSPDS1/NSKIP/NLOAD/NOFAC/S,N,MAXO/S,N,MAXI/S,N,CNTS/S,N,AITK/S,N,RESET/S,N,MINOLP/S,N,TARPEN/S,N,ADAPT/S,N,SCALMT $

Input Data Blocks:

KELM Table of element matrices for stiffness, heat conduction,differential stiffness, or follower stiffness.

PG1 Combined static load matrix for the g-set and in the residualstructure. Output by PCOMB.

KDICT KELM dictionary table

SILS Global scalar index list (required only for OPTION=1)

ECT Element connectivity table

BGPDT Basic grid point definition table

CSTM Table of coordinate system transformation matrices

EDT Table of Bulk Data entry images related to element deformation,aerodynamics, p-element analysis, divergence analysis, and theiterative solver. Also contains SET1 entries.

CASECC Table of Case Control command images. Required if SMETHODCase Control command is used and NSIP=-1.

USET Degree-of-freedom set membership table for g-set

RG Constraint matrix in g set

MPT Material property table

New Modules 311

YG Specified non-zero displacements in g set

SLT Static load table

MDICT Mass dictionary

MELM Element mass matrix

EPT Element property table

CNELM Contact/Glue element definition

ELCNST Element normal stiffness

ELCTST Element tangential stiffness

Output Data Blocks:

UGV1 Displacements - g set

QG1 SPC forces - g set

OQGCF1 Contact force at grid point.

OBC1 Contact pressures and tractions at grid points.

CONFON Contact forces on elements.

ELTRCT1 Contact tractions on elements.

OSPDSI1 Initial separation distance

OSPDS1 Final separation distance

NSKIP Input-integer-no default. Record number in CASECCcorresponding to the first subcase of the current boundarycondition.

NLOAD Input-integer-no default. Number of subcases in the contactsolution.

NOFAC Input - integer. Percent of initially open contacts to make active.

312 New Modules

Parameter:

MAXO Input-integer-no default – Maximum number of iterations for theStatus/Outer loop (BCTPARM MAXS value).

MAXI Input-integer-no default – Maximum number of iterations for theForce/Inner loop (BCTPARM MAXF value).

CNTS Input-real. Allowable number of contact changes for convergence.(Same as NCHG parameter on BCTPARM bulk data entry).

AITK Input-integer-no default – Aitken iteration flag.

RESET Input-integer-no default – Contact Reset flag specified on theBCTPARM Bulk data.

MINOLP Input-integer-no default – Minimum number of outer loops toexecute.

TARPEN Input-integer-no default. Target penetration. TARPEN is theproduct of the BCTPARM parameter PENETFAC and the effectivedepth calculated by the solver. It is used in the calculation of ascale factor that adaptively scales the contact stiffness matrixwhen PENADAPT is selected in the BCTPARM bulk entry.

ADAPT Input-integer default=0=0 adaptive stiffness option is not selected in the BCTPARM bulkentry.>0 adaptive stiffness option is selected in the BCTPARM bulkentry.

SCALMT Input-integer-no default. Maximum number of outer loopiterations to allow scaling of contact stiffness matrix.=3 for shell models=MAXO for solid models

New Modules 313

FOELCCS

Combines the normal and tangential contact penalty stiffness matrices dependingon contact status.

Format:

FOELCCS CNELM,ECSTAT,ELCNST,ELCTST,SIL/ELCSTF/S,N,CONV/S,N,CITO/S,N,NOKGGC

Input Data Blocks:

CNELM Contact element definition table.

ECSTAT Contact status vector

ELCNST Normal contact stiffness

ELCTST Tangential contact stiffness

SIL Nodal SILS

Output Data Blocks:

ELCSTF Combined contact stiffness

Parameters:

CONV Input,integer. Converged solution (=0 not converged =1 converged)

CITO Input,integer. Contact outer loop counter.

NOKGGC Output,integer. ELCSTF existence flag (= –1 does not exist, =0exists)

314 Updated Datablocks

12.3 Updated Datablocks

EPT

Element property table

New and Updated Records:

Record 1 – NSM(3201,32,991) – Nonstructural Mass

Defines the properties of a nonstructural mass.

Word Name Type Description

1 SID I Set identification number

2 PROP(2) CHAR4 Set of properties or elements

4 ORIGIN I Entry origin

5 ID I Property or element identificationnumber

6 VALUE RS Nonstructural mass value

Words 5 through 6 repeat until End of Record

Record 2 – NSM1(3301,33,992) – Alternate form of Nonstructural Mass.

Defines the properties of a nonstructural mass.



2 PROP(2) CHAR4 Set of properties or elements

4 ORIGIN I Entry origin

5 VALUE RS Nonstructural mass value

6 SPECOPT I Specification option

SPECOPT=1 By IDs

Updated Datablocks 315


7 ID I

Word 7 repeats until End of Record

SPECOPT=2 All

7 ALL(2) CHAR4

Words 7 and 8 repeat until End of Record

SPECOPT=3 Thru range

7 ID I

8 THRU(2) CHAR4

10 ID I


SPECOPT=4 Thru range with by

7 ID I

8 THRU(2) CHAR4

10 ID I

11 BY(2) CHAR4

13 N I


End SPECOPT

Record 3 – NSMADD(3401,34,993) – Nonstructural Mass Addition

Combines the nonstructural mass inputs.





2 ID I Set of properties or elements

Word 2 repeats until End of Record

Record 13 – PBUSH(1402,14,37)


1 PID I Property identification number

2 K(6) RS Nominal stiffness values

8 B(6) RS Nominal damping coefficient

14 GE(6) RS Nominal structural damping constant

20 SA RS Stress recovery coefficient in thetranslational component

21 ST RS Stress recovery coefficient in therotational component

22 EA RS Strain recovery coefficient in thetranslational component

23 ET RS Strain recovery coefficient in therotational component

Record 15 – PBUSHT(702,7,38)


1 PID I Property identification number

2 TKID(6) I TABLEDi entry identification numbersfor stiffness

8 TBID(6) I TABLEDi entry identification numbersfor viscous damping

Updated Datablocks 317


14 TGEID(6) I TABLEDi entry identification numberfor structural damping

20 TKNID(6) I TABLEDi entry IDs for force versusdeflection


GEOM3

Table of Bulk Data entry images related to static and thermal loads

Record 1 – ACCEL(7401,74,601)


1 SID I Load set identification number

2 CID I Coordinate system identification number

3 N(3) RS Components of a vector coordinate systemdefined by CID

6 DIR CHAR1 Component direction of accelerationvariation

7 LOCi RS Location along direction DIR in coordinatesystem

8 VALi RS The load scale factor associated withlocation LOCi

Words 7 through 8 repeat until (-1,-1) occurs.

Record 2– ACCEL1(7501,75,602)


1 SID I Load set identification number

2 CID I Coordinate system identification number

3 A RS Acceleration vector scale factor

4 N(3) RS Components of a vector coordinate systemdefined by CID

7 GRIDID I Grid ID or THRU or BY code

Words 7 repeats until (-1) occurs.

Updated and New Subdmaps 319

12.4 Updated and New Subdmapssekmr.datsemr3.datdmpstat.datmmrbfnd.datrotmat.datout2geom.datsol601.datsol701.datgpstress.datgentim2.datsweepit.datxortho.datphase1f.datrotsync.datstatics2.datdsamodes.datextout.datsetdropt.datdbtrans.datdsastat.datgentim.datgentims.datnlkr.datphase1e.datsekdr.datupdate.datxmergofp.datsol2c.datacmgn.datautosup.datcmpmdvm.datcforce2.datconattm.datcstrdisp.datdmpstat0.datextotmin.datextin.datfdrmgen.datgma.datmakvgac.datmoddamp.datsekr0.datsemr2.datsemrb.datstatcyc.datspdr1.datstatemg.datsemrm.datsol2.datphase1d.datselg.datselr.datstatrs.datdescon.datpslgdv.datrespsen.datsedisp.datrotloop.datcmpmode.dat

320 Updated and New Subdmaps

ifpl.datmoders.datphase1b.datsekrrs.datsemg1.datmodefsrs.datbcklfea.datxreadm.datxreadr.datdesinit.datifps.datmodcon.datprsdisp.datsemr3vm.datsuper3.datxread.datsedrcvr.dataestat.datcycbuckl.datcycfreq.datcycmode.datcycstatx.datdesopt.datdisopts.datnlstatic.datnltran.datphase1dr.datphase1a.datresddam.datseaero.datsebuckl.datsedceig.datsedfreq.datsedtran.datsefluttr.datsemceig.datsemfreq.datsemodes.datsemtran.datsestatic.datsuper1.datdisprs.datphase0.datspdr.datfea.datfreqrs.datsemg.dat

Chapter

13System Description Summary

Table 13-1. System Description – HP9000 – HP-UX

Item Description

Supported Model(s) PA-RISC

Build OperatingSystem PA-RISC: HP-UX B.11.00

Other SupportedOperating Systems HP-UX B.11.11

Word Length 32 bits

Build Type LP-64, LP-64 DMP

MPI required for DMP HP MPI 2.0.0 (comes with OS)

Table 13-2. System Description – Itanium HP-UX

Item Description

Supported Model(s) Itanium-HP-UX

Build OperatingSystem HP-UX B.11.23

Other SupportedOperating Systems

Word Length LP-64: 32 bits; ILP-64: 64 bits

Build Type LP-64, LP-64 DMP, ILP-64, ILP-64 DMP

MPI required for DMP HP MPI 1.08.02 (comes with OS)

Table 13-3. System Description – Windows (32-bit)

Item Description

Supported Model(s) Intel and Intel-compatible

Build OperatingSystem WXP SP2


Win Server 2003, WXP-64 SP1; Vista SP1

322

Word Length 32 bits

Build Type ILP-32

Table 13-4. System Description – Windows (64 bit)

Item Description

Supported Model(s) x86-64 Intel and Intel compatible

Build OperatingSystem Windows XP-64 Version 2003 SP1


Windows XP-64 SP2, Vista SP1


Build Type LP-64, ILP-64

Build Type LP-64

Table 13-5. System Description – Linux

Item Description

Supported Model(s) x86-64 Intel and Intel compatible

Build OperatingSystem Redhat 7.3


Redhat 9, Redhat EL 3.0, Redhat EL 4.0, Suse ES 9, Suse ES 10

Word Length 32 bits

Build Type ILP-32, ILP-32 DMP

MPI required for DMP HP MPI 2.02 (included with NX Nastran install)

Table 13-6. System Description – X86_64 Linux

Item Description

Supported Model(s) X86-64 Linux

Build OperatingSystem

Suse ES 9.0, Patch Level 3


Suse 9.1, Suse 9.3, Redhat EL 3.0, Redhat EL 4.0, Redhat EL 5.0, Suse ES 10



MPI required for DMP HP MPI 2.02.05 (included with NX Nastran install)

Table 13-7. System Description – Itanium Linux

323

Item Description

Supported Model(s) Itanium II

Build OperatingSystem Redhat EL3.0

Other SupportedOperating Systems Redhat EL4.0



MPI required for DMP HP MPI 2.02.05 (included with NX Nastran install)

Table 13-8. System Description – Sun SPARC – Solaris

Item Description

Supported Model(s) UltraSPARC

Build OperatingSystem UltraSPARC: Solaris 8


Solaris 9, Solaris 10

Word Length 32 bits

Build Type LP-64

Table 13-9. System Description – IBM RS/6000 – AIX (64 bit)

Item Description

Supported Model(s) Power3, Power4, Power5

Build OperatingSystem AIX 5.1


AIX 5.2, AIX 5.3, AIX 6.1



MPI required for DMP POE 3.2.0.0 (add on from IBM)

Table 13-10. System Description – SGI Altix

Item Description

Supported Model(s) SGI-ALTIX

Build OperatingSystem

SGI ProPack 3 sp4

324

Other SupportedOperating Systems SGI ProPack 4



MPI required for DMP SGI MPT 1.10 (comes with OS)

release guide 61 - smart-fem.de · additionalilp-64executableinformation 3...

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