Natural frequencies of constrained multi-body system?

[leromi]

Hello everybody.

Recently I implemented RB engine ( approach is similar as in Bullet - velocity based, both PGS and SI solvers ) for large vehicle simulation. (Works very well, the only problem is very stiff springs, and explosion as result of high amplitude motion.)

Currently, I am trying to find some reasonably easy way to run modal analysis, also calculate natural frequencies.

Has anyone had experience with frequency analysis for constrained multi-body system?
Maybe someone can point me in the right direction?

Thank you.