GregLocock,
Thank you for your answer! Unfortunately, I don't have access to this article. If it's possible and allowed could you share this paper with me?
In "Flexible Mulibody Dynamics" by Geradin and Cardona it's written that one can compute the position of the center of mass from the stiffness and mass matrices of the element. Is it realy possible? I couldn't find any information about this technics.
Does anybody have some information about it?