How to calculate Stress Intensity Factor for user defined material in abaqus?

Dear all,

I need to calculate SIF in abaqus for some user defined material but I am getting the below error:

 ***ERROR: "*CONTOUR INTEGRAL, TYPE=K FACTORS" CAN NOT BE REQUESTED FOR A USER
           MATERIAL.

Is their any other process to calculate the SIF in abaqus, in case we use user defined material. Please guide me.

Thanks in advance

Rajwinder Singh