Fourier Transformation in Nastran

[Breezer]

Who can guide me through a Fourier Transformation in Patran/Nastran? To run a modal transient analysis I need to know which modes are dominantly participating.

Thank you.

 

[tomirvine]

First, run a normal modes analysis. Then inspect the effective modal mass values in the output file. NE/Nastran outputs these values. I am uncertain whether other FEA software give these values.

You should probably include enough modes in the modal transient analysis to account for, say, at least 90% of the mass.

Also, consider the frequency content of the excitation function with respect to the modal frequencies.

Tom Irvine

http://www.vibrationdata.com

 

[LOFO]

Hello.
Does anyone knows about the use of orthotropic material in/for FEA in Generative structural analysis CatiaV5... It looks like Catia is allergic to orthotropic material data...