I am using GAP elements in a nonlinear static solution to analyze the deflection of a clamp as it presses down on ceramic block. There are discrete faces that contact the ceramic and I defined gap elements between them and the ceramic. As I increment the load, the gap elements of zero length develop forces and cause the clamp to deform as expected, however the other gap elements that just begin to close for the other faces result in the solution ending in FATAL after a string of large matrix diagonal ratios and element geometric warnings.
The model is well behaved for linear static and dynamic analysis.
I have tried variations in the GAP element stiffness and the NLPARM solution parameters with little effect on this error.
I was about to comment out the gap elements with nonzero initial length and testing the analysis again.
