Autodesk Simulation Mechanical 2014 - Can't solve assembly with surface contact

[Kaarebh]

Hey

I have a assembly of a universal joint  which I try to simulate in a static situation, and I solve for linear stress. I have some troubles getting some results when I use "surface contact" between my parts (see attached picture, set up). When I push simulate my computer just start solving and solving, but after 15 min. If comes up with some warnings, and after 8 hours it just keep repeating the same warnings. What is wrong? The funny thing is that it takes around 15 min. To solve the same situation just with bonded surfaces. And results looks very realistic 

Best regards

Kaare Bek Hansen

Mechanical student at University of Southern Denmark 

[Stefan2653 · Accepted solution]

Kaare,

Is the left linkage properly constrained where the shaft would connecto to it? If you don't have a translational constraint in X and Y there, that linkage will just flop around, resulting in the insufficient tie down error. When you bond the assembly, the left linkage is prevented from flopping and the solver will arrive at a solution, even without those translational constraints.

Stefan

[Kaarebh]

Thank you for the advise.