做接触问题时，力一加大就不收敛，这是怎么回事呢？

提示是这样的：
***NOTE: THE SOLUTION APPEARS TO BE DIVERGING. CONVERGENCE IS JUDGED UNLIKELY.
***ERROR: TIME INCREMENT REQUIRED IS LESS THAN THE MINIMUM SPECIFIED
COMPATIBILITY ERRORS:
PENETRATION ERROR TOO LARGE COMPARED TO DISPLACEMENT INCREMENT.
FORCE EQUILIBRIUM NOT ACHIEVED WITHIN TOLERANCE.
THE MOMENT IS ZERO EVERYWHERE BUT THE MOMENT RESIDUAL THE ROTATION CORRECTION IS NON-ZERO
该怎样修改呢？求懂的人指点下。