The units don't matter, that will be taken care of.

I want to see your model:
- Do you have rigid elements? If so, CAESAR II determines the stiffness differently from the other two programs you sited.
- Do you have non-linear boundary conditions? If so, maybe you linearized things differently in the CAESAR II dynamics differently.


As I said before, you should get the same result, and if you don't, the models are different.