It is the model. Very simple. Two rigid ends, the lower one is fixed. The upper one moved down to press the ball. So, why theball is hard to converge? THX!
OK, now the convergence is not a problem. THX!
How can I define a rigid contacts a point, it is easy?
In this case, I directly defined the upper point of the ball was a plane to contact with the rigid, not a point.