Fast Contact (SUPORT-based and N2S Contact-based)
Fast Contact uses a different formulation when compared to the Penalty-based approach and the SUPORT-based contact.
This is applicable in cases where the only nonlinearities in the model arise due to Contact and the model includes small deformations and small sliding.
This is also not applicable to Large Displacement Nonlinear Analysis (LGDISP). There are two approaches to Fast Contact in OptiStruct.