Vibration analysis of large assemblies

[Epack]

I am looking for some tips on which commercial FEA product can effectively handle shock and vibration analysis of very large electronics chassis assemblies like communications equipment rack loaded with circuit boards, fans, etc.

Thanks!

 

[Twoballcane]

I think they all can, it comes down to how you mesh and useing shells instead of solids. For vib, are you looking for mode shapes and Fn? For shock, you have to do your G calculations from the pulse and simply add a static gravity.

Tobalcane
"If you avoid failure, you also avoid success."

 

[izax1]

Most commercial FE codes will do the job. The challenge is to model the PCB's correctly. That is much more than defining Glass Fibre Properites, density and thickness. The componenets on the PCB will shift both stiffness and mass distribution. Do a quick shaking of the PDB and find the fundamental natural frequencies. Tune your FE model of the PCB to fit your test and include the model of the tuned PCB into your System model.

 

[Epack]

How about pre-procesors and their ability to de-feature and clean up large assemblies and mesh? Any recommendations on products like FEMAP, Patran, DesignModeler, SpaceClaim?

Thanks.

 

[GregLocock]

De-feature in your CAD environment, not in the preprocessor.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.