ANSYS Basics Chapter 3 Training Manual October 30, 2001 Inventory # Chapter 3 Memory Overview ANSYS Executable memory is the memory required for the ANSYS program. ANSYS Workspace is the memory ANSYS requires to run in addition to the ANSYS Executable memory. Real memory is the amount of actual, physical memory (RAM) available through memory chips on your machine. System virtual memory is simply a portion of the computer's hard disk used by the system to supplement physical memory. Training Manual October 30, 2001 Inventory # Chapter 3 - Memory Definitions Workspace space (i.e m ) is the memory ANSYS needs to run. Default is 64 MB on Windows machine and 128 on UNIX machines. Database space (i.e. db) is used to work with the ANSYS database. For example, model geometry, material properties, loads, etc. Defaults to 32MB on Windows and 64MB on UNIX machines. Scratch space is where all internal calculations are done. For example, element matrix formulation, frontal solution, Boolean calculations, and so on. Scratch space = Workspace - Database Training Manual October 30, 2001 Inventory # ANSYS Memory Guidelines: Use a workspace (i.e. m) of 1 Gbyte per million DOFS Use a disk space of 10 Gbytes per million DOFS Chapter 3 - Memory Limits/Guidelines ANSYS Memory Limits Training Manual October 30, 2001 Inventory # Interactive mode allows you to interact live with ANSYS, reviewing each operation as you go. Of the three main phases of an analysis preprocessing, solution, postprocessing the preprocessing and postprocessing phases are best suited for interactive mode. We will mainly cover interactive mode in this course. Chapter 3 Interactive Mode Overview Training Manual October 30, 2001 Inventory # Chapter 3 - Interactive Mode Starting ANSYS Launcher Allows you to start ANSYS and other ANSYS utilities by pressing buttons on a menu. On Windows systems, press Start > Programs > ANSYS 6.0. On Unix systems, issue tansys60 & to bring up the launcher. Training Manual October 30, 2001 Inventory # Pressing the Interactive button on the launcher brings up a dialog box containing start-up options: Chapter 3 - Interactive Mode Starting ANSYS Windows systemsUNIX systems Select Edit >>Preferences > ANSYS GUI Settings in main launcher Training Manual October 30, 2001 Inventory # Launcher (contd) After choosing the desired start-up options, press the Run button to start ANSYS. Command Line ANSYS is started by typing a command at the system level. For example: ansys60 ansys60 -g ansys60 -g -j plate ansys60 -g -p ANE3FL -d 3d -j proj1 -m 128 Chapter 3 - Interactive Mode Starting ANSYS Training Manual October 30, 2001 Inventory # Command Line (contd) Typical start-up options, commonly known as command line options, are: -g(to automatically bring up the GUI upon start-up) -pproduct_code -dgraphics_device -jjobname -mmemory The working directory is the directory in which the command is issued. Refer to your ANSYS Installation and Configuration Guide for details on the command line options. Chapter 3 - Interactive Mode Starting ANSYS Training Manual October 30, 2001 Inventory # Entering ANSYS brings up the following GUI windows: Input Displays program prompt messages and a text field for typing commands. All previously typed commands appear for easy reference and access. Main Menu Contains the primary ANSYS functions, organized by processors (preprocessor, solution, general postprocessor, etc.) Output Displays text output from the program. It is usually positioned behind the other windows and can be raised to the front when necessary. Utility Menu Contains functions which are available throughout the ANSYS session, such as file controls, selecting, graphics controls, parameters, and exiting. Toolbar Contains push buttons for executing commonly used ANSYS commands and functions. Customized buttons can be created. Graphics Displays graphics created in ANSYS or imported into ANSYS. Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Main Menu Contains the main functions required for an analysis. Independent, sticky windows allow you to complete all necessary steps before moving on to the next function. Conventions: indicates a dialog box + indicates graphical picking > indicates a submenu (blank) indicates an action Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Utility Menu Contains utilities that are generally available throughout the ANSYS session: graphics, on-line help, select logic, file controls, etc. Same conventions as Main Menu: indicates a dialog box + indicates graphical picking > indicates a submenu (blank) indicates an action Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Input Window Allows you to enter commands. (Most GUI functions actually send commands to ANSYS. If you know these commands, you can type them in the Input Window.) Also used for prompts during graphical picking. Command Syntax Chapter 3 - Interactive Mode The GUI Prompting User for Info Training Manual October 30, 2001 Inventory # Toolbar Contains abbreviations -- short-cuts to commonly used commands and functions. A few predefined abbreviations are available, but you can add your own. Requires knowledge of ANSYS commands. A powerful feature which you can use to create your own button menu system! Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Layout Three predefined menu layouts are available (Launcher > Interactive > GUI Configuration): Input window on left (default) Input window on right Input window on bottom You can also create your own layout and then save it using Utility Menu > MenuCtrls > Save Menu Layout. Unix systems store the layout in an ASCII resource file called ANSYS60, located in $HOME. Windows systems store the layout in the system registry. Input Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Preferences The Preferences dialog (Main Menu > Preferences) allows you to filter out menu choices that are not applicable to the current analysis. For example, if you are doing a thermal analysis, you can choose to filter out other disciplines, thereby reducing the number of menu items available in the GUI: Only thermal element types will be shown in the element type selection dialog. Only thermal loads will be shown. Etc. Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Other GUI Notes Some dialog boxes have both Apply and OK buttons. Apply applies the dialog settings, but retains (does not close) the dialog box for repeated use. OK applies the dialog settings and closes the dialog box. The Output Window is independent of the ANSYS menus. Caution: Closing the output window closes the entire ANSYS session! Remember that you are not restricted to using the menus. If you know the command, feel free to enter it in the Input Window! Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # Demo: Start ANSYS using the launcher Show the various parts of the GUI Bring up Keypoints in Active CS dialog box and show the difference between OK and Apply Show the Preferences dialog Explain the Output window Chapter 3 - Interactive Mode The GUI Training Manual October 30, 2001 Inventory # The most heavily used interactive capabilities are graphics and graphical picking. Graphics is used to visualize the model, loading, results, and other input and output data. Picking is used for model creation, meshing, loading, etc. Use Plot in the Utility menu to produce plots, or issue the commands shown. Chapter 3 - Interactive Mode Graphics and Picking /replot kplot lplot aplot vplot nplot eplot gplot Training Manual October 30, 2001 Inventory # The PlotCtrls menu is used to control how the plot is displayed: plot orientation zoom colors symbols annotation animation etc. Among these, changing the plot orientation (/VIEW) and zooming are the most commonly used functions. Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # The default view for a model is the front view: looking down the +Z axis of the model. To change it, use dynamic mode a way to orient the plot dynamically using the Control key and mouse buttons. Ctrl + Left mouse button pans the model. Ctrl + Middle mouse button: zooms the model spins the model (about screen Z) Ctrl + Right mouse button rotates the model: about screen X about screen Y P ZR Ctrl Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # If you dont want to hold down the Control key, you can use the Dynamic Mode setting in the Pan-Zoom-Rotate dialog box. The same mouse button assignments apply. On 3-D graphics devices, you can also dynamically orient the light source. Useful for different light source shading effects. Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Other functions in the Pan- Zoom-Rotate dialog box: Preset views Zoom-in on specific regions of the model Pan, zoom, or rotate in discrete increments (as specified by the Rate slider) Rotation is about the screen X, Y, Z coordinates. Fit the plot to the window Reset everything to default Front+Z view, from (0,0,1) Back-Z view (0,0,-1) Top+Y view (0,1,0) Bot-Y view (0,-1,0) Right+X view (1,0,0) Left-X view (-1,0,0) IsoIsometric (1,1,1) ObliqOblique (1,2,3) WPWorking plane view ZoomBy picking center of a square Box ZoomBy picking two corners of a box Win ZoomSame as Box Zoom, but box is proportional to window. Back UpUnzoom to previous zoom. Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Picking Picking allows you to identify model entities or locations by clicking in the Graphics Window. A picking operation typically involves the use of the mouse and a picker menu. It is indicated by a + sign on the menu. For example, you can create keypoints by picking locations in the Graphics Window and then pressing OK in the picker. Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Two types of picking: Retrieval picking Picking existing entities for a subsequent operation. Allows you to enter entity numbers in the Input Window. Use the Pick All button to indicate all entities. Locational picking Locating coordinates of a point, such as a keypoint or node. Allows you to enter coordinates in the Input Window. Example of Retrieval Picker Example of Locational Picker Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Mouse button assignments for picking: Left mouse button picks (or unpicks) the entity or location closest to the mouse pointer. Pressing and dragging allows you to preview the item being picked (or unpicked). Middle mouse button does an Apply. Saves the time required to move the mouse over to the Picker and press the Apply button. Use Shift-Right button on a two- button mouse. Right mouse button toggles between pick and unpick mode. Pick Apply Toggle Pick / Unpick Unpick Pick Cursor display: Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Hotspot locations for picking: Areas and Volumes have one hotspot near the centroid of the solid model entity. Lines have three hotspots - one in the middle and one near each end. Why this is important: When you are required to pick an entity, you must pick on the hotspot. Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # Demo: Show locational picking by creating a few keypoints. Also show the use of middle and right mouse buttons. Show retrieval picking by creating a few lines Show Loop by creating an AL area Show Pick All by deleting area only Do KPLOT, LPLOT, etc. with and without numbering. Type in a few of these commands. Show the use of pan-zoom-rotate Chapter 3 - Interactive Mode Graphics and Picking Training Manual October 30, 2001 Inventory # ANSYS uses an HTML-based documentation system to provide extensive on-line help. You can get help on: ANSYS commands element types analysis procedures special GUI widgets such as Pan-Zoom-Rotate You can also access: Tutorials Verification models The ANSYS web site Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # There are several ways to start the help system: Launcher > Help System Utility Menu > Help > Help Topics Any dialog box > Help Type HELP,name in the Input Window. Name is a command or element name. Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # Pressing the Help System button on the launcher brings up a help browser with: a navigational window containing Table of Contents, Index, and a Search Utility a document window containing the help information. Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # Use the Contents tab to browse to the item of interest. Use the Index tab to quickly locate specific commands, terminology, concepts, etc. Use the Search tab to query the entire help system for specific words or phrases. Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # ANSYS also provides an HTML-based on-line tutorial. The tutorial consists of detailed instructions for a set of problems solved in ANSYS. To access the tutorial, click on Utility Menu > Help > ANSYS Tutorials. Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # Demo: Launch the help system from the launcher Bring up an Analysis Guide Type help,kplot in the Input window Search for the string harmonic response Chapter 3 - Interactive Mode On-Line Help Training Manual October 30, 2001 Inventory # Suppose you wanted to do the following: Plot all areas located in the second quadrant Delete all arcs of radius 0.2 to 0.3 units Apply a convection load on all exterior lines Write out all nodes at Z=3.5 to a file View results only in elements made of steel The common theme in these tasks is that they all operate on a subset of the model. Select Logic allows you to select a subset of entities and operate only on those entities. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Three steps: Select a subset Perform operations on the subset Reactivate the full set Reactivate full set Select subset Operate on subset Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Selecting Subsets Most selecting tools are available in the Select Entities dialog box: Utility Menu > Select > Entities... Or you can use the xSEL family of commands: KSEL, LSEL, ASEL, VSEL, NSEL, ESEL Entity to select Criterion by which to select Type of selection Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Criterion by which to select: By Num/Pick: to select based on entity numbers or by picking Attached to: to select based on attached entities. For example, select all lines attached to the current subset of areas. By Location: to select based on X,Y,Z location. For example, select all nodes at X=2.5. X,Y,Z are interpreted in the active coordinate system. By Attributes: to select based on material number, real constant set number, etc. Different attributes are available for different entities. Exterior: to select entities lying on the exterior. By Results: to select entities by results data, e.g, nodal displacements. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Select None Type of selection From Full: selects a subset from the full set of entities. Reselect: selects (again) a subset from the current subset. Also Select: adds another subset to the current subset. Unselect: deactivates a portion of the current subset. Invert: toggles the active and inactive subsets. Select None: deactivates the full set of entities. Select All: reactivates the full set of entities. Reselect Also Select Unselect Invert From Full Select All Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Operations on the Subset Typical operations are applying loads, listing results for the subset, or simply plotting the selected entities. The advantage of having a subset selected is that you can use the [Pick All] button when the picker prompts you pick desired entities. Or you can use the ALL label when using commands. Note that most operations in ANSYS, including the SOLVE command, act on the currently selected subset. Another operation is to assign a name to the selected subset by creating a component (discussed in the next section). Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Reactivating the Full Set After all desired operations are done on the selected subset, you should reactivate the full set of entities. If all nodes and all elements are not active for solution, the solver will issue a warning to that effect. The easiest way to reactivate the full set is to select everything: Utility Menu > Select > Everything Or issue the command ALLSEL You can also use the [Sele All] button in the Select Entities dialog box to reactivate each entity set separately. (Or issue KSEL,ALL; LSEL,ALL; etc.) Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Components are named subsets. The name can then be used in dialog boxes or commands in place of entity numbers or the label ALL. A group of nodes, or elements, or keypoints, or lines, or areas, or volumes can be defined as a component. Only one entity type is associated with a component. Components can be selected or unselected. When you select a component, you are actually selecting all of the entities in that component. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # To create a component: First select the desired subset of entities. Then name the subset using the CM command or Utility Menu > Select > Comp/Assembly > Create Component Up to 8 characters letters, numbers, and _ (underscore) are allowed for the name. Beginning a component name with _ (underscore) will make it a hidden component and it cannot be picked from a list. This is NOT recommended. Suggestion: Use the first letter of the name to indicate the entity type. For example, N_HOLES for a node component, E_ALUMIN for an element component, etc. Reactivate all entities. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # Some useful options: Plot components Utility Menu > Plot > Components > Selected Components Or CMPLOT Select, unselect, reselect, etc. Utility Menu > Select > Comp/Assembly > Select Comp/Assembly Or CMSEL Listing components gives a list of currently defined and selected components. Utility Menu > Select > Comp/Assembly > List Comp/Assembly Or CMLIST Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # An assembly is a group of components. An assembly can also be made up of one or more other assemblies and/or components. The groups that make up assemblies can consist of any combination of entity types. To create an assembly: Utility Menu > Select > Comp/Assembly Or use CMGRP You can nest assemblies up to 5 levels deep. For example, an assembly named MOTOR may be built up from other assemblies and components, as shown on the next page. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # MOTOR ROTORASM (Volumes & Lines) AIRGAP (Elements) STATASM (Volume & Elements) STATOR (Volume) PERMMAG (Elements) ROTOR (Volume) WINDINGS (Lines) ComponentsAssembliesAssembly The assembly MOTOR consists of Volumes, Elements, and Lines. Chapter 3 - Interactive Mode Select Logic Training Manual October 30, 2001 Inventory # The term ANSYS database refers to the data ANSYS maintains in memory as you build, solve, and postprocess your model. The database stores both your input data and ANSYS results data: Input data -- information you must enter, such as model dimensions, material properties, and load data. Results data -- quantities that ANSYS calculates, such as displacements, stresses, strains, and reaction forces. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Save and Resume Since the database is stored in the computers memory (RAM), it is good practice to save it to disk frequently so that you can restore the information in the event of a computer crash or power failure. The SAVE operation copies the database from memory to a file called the database file (or db file for short). The easiest way to do a save is to click on Toolbar > SAVE_DB Or use: Utility Menu > File > Save as Jobname.db Utility Menu > File > Save as SAVE command Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # To restore the database from the db file back into memory, use the RESUME operation. Toolbar > RESUME_DB Or use: Utility Menu > File > Resume Jobname.db Utility Menu > File > Resume from RESUME command The default file name for SAVE and RESUME is jobname.db, but you can choose a different name by using the Save as or Resume from functions. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Notes on SAVE and RESUME: Choosing the Save as or Resume from function does NOT change the current jobname. If you save to the default file name and a jobname.db already exists, ANSYS will first copy the old file to jobname.dbb as a back-up. The db file is simply a snapshot of what is in memory at the time the save is done. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Tips on SAVE and RESUME: Periodically save the database as you progress through an analysis. ANSYS does NOT do automatic saves. You should definitely SAVE the database before attempting an unfamiliar operation (such as a Boolean or meshing) or an operation that may cause major changes (such as a delete). RESUME can then be used as an undo if you dont like the results of that operation. SAVE is also recommended before doing a solve. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Clearing the Database The Clear Database operation allows you to zero out the database and start fresh. It is similar to exiting and re-entering ANSYS. Utility Menu > File > Clear & Start New Or use the /CLEAR command. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Files ANSYS writes and reads several files during an analysis. File names are of the format jobname.ext. Jobname A name you choose while starting ANSYS, up to 32 characters. Defaults to file. Can be changed within ANSYS with the /FILNAME command (Utility Menu > File > Change Jobname). Extension Identifies the contents of the file, such as.db for database. Usually assigned by ANSYS but can be defined by user (/ASSIGN). Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Typical files: jobname.log: Log file, ASCII. Contains a log of every command issued during the session. If you start a second session with the same jobname in the same working directory, ANSYS will append to the previous log file (with a time stamp). jobname.err: Error file, ASCII. Contains all errors and warnings encountered during the session. ANSYS will also append to an existing error file. jobname.db,.dbb: Database file, binary. Compatible across all supported platforms. jobname.rst,.rth,.rmg,.rfl: Results files, binary. Contains results data calculated by ANSYS during solution. Compatible across all supported platforms. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # File Management Tips Run each analysis project in a separate working directory. Use different jobnames to differentiate various analysis runs. You should keep the following files after any ANSYS analysis: log file (.log) database file (.db) results files (.rst,.rth, ) load step files, if any (.s01,.s02,...) physics files (.ph1,.ph2,...) Use /FDELETE or Utility Menu > File > ANSYS File Options to automatically delete files no longer needed by ANSYS during that session. Chapter 3 - Interactive Mode The Database and Files Training Manual October 30, 2001 Inventory # Three ways to exit ANSYS: Toolbar > QUIT Utility Menu > File > Exit Use the /EXIT command in the Input Window Chapter 3 - Interactive Mode Exiting ANSYS Training Manual October 30, 2001 Inventory # In batch mode, ANSYS reads commands from an input file you supply, and writes responses to an output file. The process runs in the background, freeing up your computer for other work. Of the three main phases of an analysis preprocessing, solution, postprocessing the solution phase is best suited for batch mode. Thus a batch input file could be as simple as: resume,...! Resume database from preprocessing session /solu solve finish Chapter 3 Batch Mode Overview Training Manual October 30, 2001 Inventory # ANSYS is a command-driven program and can accept commands from several sources: from GUI dialog boxes (which simply send commands to ANSYS when you press OK or Apply) from the keyboard from input files An efficient way to run ANSYS, especially when you are rerunning a previous analysis, is to use input files containing the desired command sequence: Utility Menu > File > Read Input from or the /INPUT command (The start file is just an input file that is automatically read at start- up by a built-in /input command.) Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # For example, you can create a file called rectangle.inp containing the following lines: /prep7! Enter preprocessor rect,0,3,0,1! Create a 3x1 rectangle aplot and then read it into ANSYS: /input,rectangle,inp! or File > Read Input from The ! character above indicates a comment and can be used to: annotate the input file with explanations. comment out an entire command. Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # You can use the log file jobname.log as an input file. Keep in mind the following points when you do this: The log file records all commands executed during an ANSYS session. Always use a copy of the log file, dont just rename it. It may be helpful to edit the copy first and: add descriptive comments clean it up by removing erroneous commands and graphics commands (/view, /focus, /dist, etc.) add prompting commands (*ASK) Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # Session Editor Powerful ANSYS Undo ANSYS keeps a running copy of your log file from your last save command. By modifying the values in the Session Editor window and clicking OK, the modified commands are read back into ANSYS. Main Menu > Session Editor Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # The *ASK Command *ASK prompts the user for input and assigns the response to a parameter. For example, you can modify rectangle.inp as follows: /prep7! Enter preprocessor *ask,w,WIDTH OF RECTANGLE,3 rect,0,w,0,1! Create a wx1 rectangle aplot When you input this file into ANSYS, you will see the prompt shown below. Your response, say 5.2, is assigned to the parameter w, which is used in the subsequent RECT command. Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # *ASK, Par, Query, DVAL Par is the parameter name to which the response value is assigned. Query is the prompt string, up to 32 characters. The word ENTER automatically appears as the first word of the prompt. DVAL is the default value assigned to Par if the response is blank. Chapter 3 - Batch Mode Input files Training Manual October 30, 2001 Inventory # To start a batch run, use the Batch button on the launcher, or use the -b option if using the command line to start ANSYS: For example, ansys60 -b -m 128 -db 16 file.out & Chapter 3 - Batch Mode Submitting a batch job Windows systems UNIX systems Training Manual October 30, 2001 Inventory # Refer to your Workshop Supplement for instructions on: W3A Introductory Workshop W3B. Silo W3C. Impeller Chapter 3 ANSYS Basics Workshops