In the previous reply, the developer had explained:
"The J integral is an energy measure, related to the energy released for an infinitesimal increase in crack length. It will consider all loading modes (opening, shearing, twisting) “lumped” so to say. It will consider mixed mode loading, but it will not be possible to distinguish between the modes ...
The infinitesimal crack length increase is assumed to occur along the local x – direction. So in the images, the Crack opening direction must be (0, 1, 0) and it does not depend on the loading, only the geometry. "
I believe this should answer your question.