Fracture criteria on kinking of a crack out of the interface in dissimilar materials

The authors deal with fracture criteria on kinking of an interface crack out of the interface in dissimilar materials based on the maximum stress (σθmax) concept similar to the mixed-mode fracture criterion for a crack in a homogeneous material. If the bimaterial constant e of dissimilar materials is zero or small, the kinking angles can easily be determined independent of the distance r from a crack tip. However, if e becomes large, the kinking angles cannot be determined and the angles strongly depend on the distance r due to the oscillation singularity. This criterion is compared with the energy release rate criterion of He and Hutchinson.