Hello,
I want to arrange a crack propagation in a screw thread. Therefor I use two dimensional axissymmetric elements in Abaqus 6.12-3 (it is the first version, that allows XFEM in axissymmetric models). The boundaries of the screw thread are on the one hand the symmetry axis, on the other hand the contact to a nut thread that is hold in vertical direction. Thus, there are two nonlinear problems: 1.) the contact problem and 2.) the XFEM crack growth.
1.) Arranging the analysis of the contact problem without crack growth works thoroughly.