Modal analysis and stresses

[descatia]

I know how to do a modal analysis both in FE and in simple cases by hand.
How does one calculate the stresses induced in a structure due to vibration. What is a forcing function and how is that used in the FE model? Can somebody please show me a few threads or papers or books that show how to do this.

 

[PicoStruc]

You need to read about "Response Spectrum Combination or Superposition"

 

[descatia]

thanks picostruc, please give me some links, or a part of the Nastran manual etc. What solution number do you use for nastran? I know that static is solution 101 and modal is solution 106, where do i go after that?