I am testing a two-beam (3D) configuration where one beam is pushed with a force to make contact with
the other beam, I got this fairly quickly running in SOL 601,106. But I can't get it running with SOL 401, so I want
to increase the number of iterations, I increased the number of MAXS and MAXITER but the iterations still won't
go beyond 20. Am I missing here the obvious?
Thanks for your time.
what sort of info do you get (in .f06 or other files) ? Nastran should stay why is stopping the analysis
Do you have bolt preload in your model ?
If yes, do please note that default ITRBOLT(Maximum number of bolt iterations) value of NLCNTL card is 20.
If not, check your f06 and confirm which iteration has reached max.
In a nonlinear analysis, there are many reasons why an increment will stop, so it's difficult to speculate without seeing the full history. Can you post the .f06 file from the run?
Looking at your f06 output, at time=0.35, there seems to be large penetrations in the contact pair. As a result, the solution is struggling to converge. It won't matter if you increase the number of iterations because there is divergence happening even before hitting 20 iterations and contact forces a bisection to occur. Even upon bisection, its still having difficulty due to the large penetrations. Can you set LGDISP to 1 (turn on large displacements) and also set KUPDATE to 1 (turn on stiffness updates)? This may help.