XFEM 问题收敛错误疑问

syxixi

在用xfem算一个结构的时候出现下面错误信息，请问是啥原因，谢谢
Output request status is not available for the material for element type c3d8r

Abaqus IS UNABLE TO ESTIMATE AN AVERAGE INTERFACE ELEMENT LENGTH. THE WHOLE MODEL CHARACTERISTIC ELEMENT LENGTH IS USED INSTEAD