INTERFACE FRACTURE IN ABAQUS

Hiii alll,

How can we calculate J integral of interface fracture. I'm trying to reproduce results of Hutchinson paper crack defection at an interface between dissimilar material. But while using VCCT im confused that what value i can give for crack growth parameter G1c, G2c..how can we get G1c and G2c for an interface, is it needed. Want to find the energy release rate of deflection at the interface. The material interface is of aluminium and aluminium oxide. Please do reply.Hope u understand my problem.

Thank you...