There are several different issues that can cause non-convergence. A suggested methodology to determine the cause and obtain results is:

1 - Get results to evaluate the trouble.

2 - Focus only on the Load Case that is presently not converging.

3 - Find a simple Open/Close situation and make it linear – NOTE THE CHANGE.

4 - Rerun.

5 - Remove more of these simple Open/Close situations if necessary to get convergence.

6 - Check the “error” in the results for this load case.

7 - If still no solution and only friction remains, select a friction support and either 1) lock down the node or 2) remove mu at that node (again, simplify, make it more linear – all you want is a look into the results to decide).

8 - Note that if you have to remove several nonlinearities, you may be able to reinsert some of them when you finally pick the right one.

So, linearize and review the impact.