After you have defined the crack, you must use the History Output Request editor in the Step module to include the contour integral data in the output database generated by the analysis. The editor allows you to configure the following:
The output frequency.
The type of contour integral calculation to perform (-integral, -integral, stress intensity factors, or -stress).
The number of contours to evaluate.
For detailed instructions, see Requesting contour integral output, Section 20.1.13. For more information, see Modifying history output requests, Section 14.11.3, and Contour integral evaluation, Section 7.10.2 of the ABAQUS Analysis User's Manual.