Hi,

I am setting up a 2D model in ABAQUS with a block (rectangle) and an analytical rigid surface (line and arc) on the top. I define a hard contact between the rigid surface and the block and I apply the vertical load at the reference point for the rigid surface. The bottom is assigned with a YsymBC and the corner point is pinned to make the whole structure fully constrained. 

The problem is, if I do not have the arc for the rigid surface, the simulation can be completed. But once I add the arc, it will fail at the first time increment. I am wondering why. Thanks!