Introduction to Actran Release 13 Release Highlights
Jonathan Jacqmot
30 October 2012
• A quick introduction to the Actran software
• Actran R13.0 Release Highlights
• Actran R13.0 Requirements
• Summary
Agenda
The Actran Software Suite
Actran Vibro-Acoustics Actran Aero-Acoustics Actran TM
Actran Acoustics
Actran DGM
Actr
an V
I
Actran for Nastran
FE domain
IE domain • Acoustic FEM/IFEM approach
• Multi-purpose toolbox: several computational sequences
– Direct Frequency Response
– Modal Frequency Response – for interior problems
– Hybrid Modal-Physical Response – the best of both worlds
– Modal Extraction – for undamped structure or cavity
– + Compressible Flow –potential flow solver
– + Frequency response using a time domain LEE Solver = Actran DGM
– + Transient solver
• Linux or Windows platforms
• Direct & iterative solvers, multiple load & restart
• Several types of parallelism available
Actran Solver
• Improved Physics
– Rigid body elements
– Porous Miki model
• Boundary Conditions
– BC_MESH Integration method
– Actran DGM: Velocity BC
– Actran DGM: Thompson BC
– Actran DGM: Transfer admittance
– Perfectly Matched Layers
• Analysis Schemes
– Combination of modal/physic approach and staggered solver
• Inputs/Outputs
– Selection of output requests
– Specification of tolerance lists
– Specification of storage nodes for modal components
– Handling of names for all components, materials, tables, …
• High Performance Computing
– Parallelism for Aero-Acoustic computations
– Reduction of parallel NFF databases
– Actran DGM: performance improvements
– 1st level Multi-parallelism
What is New in R13.0 in a Nutshell
• Ease of Use
– Minimal number of elements per wavelength are
indicated during the computation
– Thickness of a composite can be retrieved
automatically
– NAS2ACT utility
– RADACT supports multiple loadcase
computations
– Support of a global damping in a composite
material
– ICFD: supersonic flows regularizations
– ICFD: Make CFD periodic in space
– ICFD: Symmetry of flow fields
• Actran VI
– Reading comments from external formats
– Reading comments from NFF databases,
including the mode orders, …
– Picking nodes is now enabled, allowing to create
storage nodes, measuring distances or to
interpret results in the PLTViewer
– Validating an Actran analysis in Actran VI
– Inertias of beams can now be visualized
– Automatic detection of modal basis parameters
– Visualization of boundary conditions
• Description:
– Alternative/complement to infinite elements for the
radiation in free field
– Extra-layer of finite elements used to
progressively damp the acoustic wave non-
reflecting boundary condition
• Application: Larger models and higher
frequencies
• Benefits: Lower CPU requirements
• Remarks:
– SPL available in far field thanks to fully automated
FWH solver
– Infinite elements should be preferred for low
frequencies analysis
– Not compatible with convected wave analysis
Perfectly Matched Layers (PML)
• Description: Model rigid structural or
acoustical connections
– Equivalent to Nastran’s RBE2
elements for structural connections
– Applicable to fluid
– Selective degrees of freedom
connections
• Benefit: Improve the accuracy of
complex vibro-acoustic models
• Applications:
– Rigid connections between different
parts
– Distributed punctual loads
– Selective transmission of motion
Rigid Body Elements
BEGIN COMPONENT 1
RIGID_BODY
DOMAIN rigid_body_element
DOF_TO_LINK IMMMMMM
END COMPONENT 1
• Description:
– Semi-empirical model
– Only the flow resistivity required
• Benefit: More accurate representation
than Delany-Bazley model
• Comparison of the formulations on impedance tube test
Miki Porous Model
Porous
Rigid support
Low density foam Plastic foam (rigid) High density foam
BEGIN COMPONENT 1
MIKI_POROUS
MATERIAL 1
DOMAIN Porous_domain
END COMPONENT 1
• Description:
– Model real-world microphones sensitive to the frequency and
the directivity of the acoustic field (mic. dimensions, electrical
and mechanical impedance,…)
– Directive microphones available as a complement to
conventional “ideal” field points
• Benefit: Improve the fidelity of the numerical models
• In practice: The pressure field computed at the field point
will be corrected according to the directivity of the micro &
the incidence angle of the acoustic wave
Directive Microphones
Ι
refV
0°
90°
180°
Ref. direction [x,y,z]
refV
)p(f).c(f)(fpc ,,
BEGIN MICROPHONE 2
MICROPHONE_FRF TXT frf.txt
MICROPHONE_DIRECTIVITY TXT directivity.txt
REFERENCE_DIRECTION 0. 0. 1.
1
20000 0.5 0.0 0.0
END MICROPHONE 2
• Description: As for aero-acoustic sources, Actran can use the integration
method for mapping the vibration levels for a radiation analysis
• Application: Radiation of any vibrating structure such as a gearbox or a
powertrain
BC Mesh – Integration Method 1
Acoustic nodes (coarse) Possible loss
of information
Linear interpolation from the structure mesh to the acoustic nodes
structure mesh (fine)
Standard sampling
structure nodes (fine)
acoustic nodes (coarse) All information is conserved
in the process !
Integration
mapping
• Benefits: coarser acoustic meshes can be used
– Computation time reduced and resource saved
– Higher frequencies can be reached
BC Mesh – Integration Method 2
• In practice: use keyword
METHOD INTEGRATION
BEGIN BC_MESH 1
NFF structure.nff
SURFACE 1
TOLERANCE_LIST 1
BC_FILE structure.nff
BC_FORMAT NFF
DISPLACEMENT
METHOD INTEGRATION
END BC_MESH 1
NEW
INTEGRATION
METHOD
STANDARD
SAMPLING
METHOD
• Description: a translator can be directly accessed from Actran VI
– Most relevant Nastran cards for vibro-acoustics are supported and interpreted:
• Most shells, solids, fluids including infinite fluids …
• RBE2, CBUSH, CELAS, CONM2, …
• FREQ, FORCE, SPC1, …
– Element depending information in Nastran cards are translated into FIELDs
– Compression of PIDs can be automated
– Equivalent Nastran input file is created for comparing the equivalence of the Actran case
• Benefits:
– Create Actran vibro-acoustic model easier and faster. Easier and faster creation of Actran vibro-
acoustic model
– Improve/update the translated model with Actran features (visco-thermal elements, porous
elements, …)
Nastran to Actran Translator
Nastran
input file
Equivalent Nastran
input file
Actran Input
FIELDs containing:
•Element orientation
•Offsets
•…
• Benefit: Increase the clarity of imported meshing data
• Description:
– Comments provided in Bulk Data Files can now be interpreted from:
• Ansa
• Patran
• And others
– Actran comments are now also stored in the NFF result database to
ease the display of results
Actran VI: Management of Comments
• Node picking selection has been improved to:
1. Create 0D entities directly into the mesh
2. Access FRF results from an imported map
3. Measure distances and/or angles between different nodes
Actran VI: Node Picking Enhancements
1 2
3
• Description: visualize the following imposed conditions for any
structure node
– displacement
– rotation
– point load
– point moment
• Benefit: Better control of the application of boundary conditions within
Actran VI
Actran VI: Visualize Boundary Conditions
• Description & benefit: Simulation results can be heard directly from
PltViewer using your favorite audio player!
• In practice:
1. right-click on any point fluid pressure result and select “Convert to audio”
2. A .wav file will also be generated
PltViewer: Listen to your Simulation Results
• Ease of use
• Performance
• Multiple new capabilities
• Key Highlights
– Perfectly Matched Layers (PML)
– Rigid Body Elements
– Integration Method for Radiation Analysis
– Nastran To Actran translator
– Actran VI improved look and feel
• Please download and enjoy Actran 13 !
Summary
Thank you for your attention!