I am trying to analyze a simple Hertz contact problem in 3D - sphere (or actually half of a sphere because the top part is not needed) on a flat plate. I use symmetry in two planes and the plate is fixed on the bottom face. However, because of the fact that I want to apply force to the sphere instead of using prescribed displacement, there’s one rigid body motion left that prevents the analysis from converging. Contact should eliminate it but apparently, it’s not properly established at the beginning of the analysis. Both parts are touching initially but just at one point (as always with such geometry). In Abaqus I would use stabilization functionality that applies some damping to support the model until the contact is fully established. But it seems that there’s no option like that in CalculiX. Are there any workarounds ? How would you handle such a problem ?