Tips & Tricks

Imported modal damping from NASTRAN
How do I use imported modal damping from NASTRAN?, VA One can read the modal damping matrix from Nastran (KHH or BHH matrix). The KHH or BHH matrix needs to be in the.op2 file with the modes
Emna Ben Ali Vibro-Acoustics

I have a DAF and a cavity wetting the same plate, and get unexpected cavity mass law - why?
A model like this is not valid, i.e. a DAF is not intended to be combined with a cavity like this ...
Emna Ben Ali Vibro-Acoustics

How do I work with only imported geometry for creating temporary nodes for subsystem creation?
In order to import the geometry, and use this for creating new temporary nodes, select to import “Geometry (nodes and elements)”. Then in the visibility tree, uncheck “Imported nodes” under Imported “CAD/FE Geometry”, and make “Nodes on Visible Objects” checked.
Emna Ben Ali Vibro-Acoustics

Difference in BEM solve times when recovering Radiation Efficiency. Is this expected?
I see a drastic difference in BEM solve times when recovering Rad Eff. Is this expected?, Yes, computing the BEM radiation efficiency is very expensive as it has to recover the velocity at every wetted node and multiply by the mode shape at that mode, then sum that all up.
Emna Ben Ali Vibro-Acoustics

What is the recommended mesh density for RAYON BEM and FMM BEM?
For standard BEM one can start with 6-8 elements, and refine from there. For collocation (used by the FMM solver) the guideline should be 6 to 10 elements.
Emna Ben Ali Vibro-Acoustics

Workaround for using VPS 2014 DMP modal data in VA One (internal)
It is possible to export the modes in erfh5 format of type 1. You have for that to setup the following environment variable: PAM_OCTRL_ERFVERSION=1 PSM is much faster than BLOCK_IRAM.
Emna Ben Ali Vibro-Acoustics

What is the GUI process when creating a manual point junction?
the process in the GUI, when creating a manual point junction is as follows ...
Emna Ben Ali Vibro-Acoustics

Difference between using an external vs. internal FE solver in VA One
In brief, what’s the difference between using an external vs. internal FE solver in VA One? The background is that VA One is using structural modes for FE and for FE/SEA hybrid. These modes can come from two sources: - Internal VA One Solver - External solver (NASTRAN, ANSYS, ABAQUS etc.)
Emna Ben Ali Vibro-Acoustics

How to manually set the megawords variable in Rayon?
The megaword variable can be set by specifying the value at the end of the irpoc line in the startrayon.bat file:
Emna Ben Ali Vibro-Acoustics

Can I set RAYON to solve in batch using a script in VA One?
There is no API call for launching BEM runs ...
Emna Ben Ali Vibro-Acoustics