请问这个问题怎么解决

ansys模型 单元数大概15万 有接触单元 模型中有螺栓 荷载分两步施加 一：螺栓预紧力 二：外界荷载 第一步荷载预紧力计算成功 第二步荷载一计算 就出现以下错误，求怎么回事？怎么解决？谢谢




0***** input argument error reported by subroutine xdslvv
see xdslvv abstract (ier = -402)
0***** process error reported by subroutine xdslvf
see xdslvf abstract (ier = -400)

*** ERROR *** CP = 14797.422 TIME= 17:52:00
Sparse Matrix Solver failure. Please check the error file for
possible causes.
*** ERROR *** CP = 14797.438 TIME= 18:11:29
Bisection may be activated if it is a nonlinear analysis.