Issue when analysing assembly with preload, finite friction contact and large deformation

Hello all,

I decided to share this after getting, I think, similar issues since Simulate 2.0 and finally finding now a good clue when using Simulate 4.0.

I don´t know if this issue is present in different Creo version and datacodes.

If you use contact with finite friction you must use LDA. If you have the option to not use LDA you may not have this problem.

This simple assembly model (picture) shows a bad combination of features that finishes with:

“*** A fatal error has occurred. *** The nonlinear iteration did not converge for the time value: 0.00000e+00 »

_ What is odd is that this happen only if you are using « single-pass adaptive » and only on the 2nd pass. The 1st pass finished without problem. If you use “quick check” you will not have this problem.

This model has an initial interference to simulate preload and two finite friction contact regions – one between the flanges and one between the head of the screw and the flange.

In short, if “Rigid link” is present – even if it does participate directly in the regions being deformed – the simulation will fail on the 2nd pass (already during preload).

If RL is replaced by weighted-links, the simulation works.

If RL is present and the top contact is suppressed, the simulation works.

If RL is suppressed, the simulation works.

Yes, Creo advices that links and LDA may produce wrong results. However, the above combination looks more like a bug than a wrong result.

So, an old advice in case of odd fails or bad results in LDA – start by suppressing the links when possible.

Hopefully this info can help someone.

Best regards

R. Rabe