Prediction of the propagation direction of a crack that attacks the interface at an arbitrary angle

The problem of a crack subjected to uniaxial tension, approaching an interface between the two materials at an arbitrary angle, is considered. Prediction of the crack propagation was based on the linear elastic fracture mechanics (LEFM) concept. Obtained results show that the crack that attacks the interface at a right angle, coming from the softer material, would not penetrate the interface and would not continue to propagate across it, but that it would bounce back to the material it is coming from and continue to propagate along the path close to the interface. The similar situation is for the crack attacking the interface at an angle of 75°. It would also bounce away from the interface, though it might also deflect into it if the interface was weak. For the attack angle of 60°, as well as for the smaller angles, the crack would penetrate the interface and continue to propagate in the material across it. The prediction of the crack propagation direction was done for the two bimaterial combinations. Based on results, presented in this paper, it is possible to establish the criteria for predicting the propagation direction of a crack attacking the interface at an arbitrary angle.