Rigid body motion

[gurmeet2003]

I have an assembly with a large number of parts with contacts. I am solving for a pressure load. I get a max to min coeff. ratio that is very large. My model never converges. I suspect it is due to rigid body motion. I have carried out a modal analysis of the assembly and sub-assemblies and no unexpected rigid body modes are seen,except for those due to open contacts.

I suspect that the rigid body motion is due to initial state of contacts. The contacts are all frictionless. Could someone please suggest what are the different options I have to resolve this problem?

Thanks in anticipation.

Gurmeet
Time is an illusion. Now is the only thing there is.

 

[Maud35]

Have you already tried the contact stabilization ?

'For standard contact (KEYOPT(12) = 0) or rough contact (KEYOPT(12) = 1), you can use real constants FDMN and FDMT to define contact damping scaling factors along contact normal and tangential directions. The primary goal of this contact stabilization technique is to damp relative motions between the contact and target surfaces for open contact. It provides a certain amount of resistance to reduce the risk of rigid body motion.'