Effect of virtual crack size on the crack deflection criterion at a bi-material interface under wedge loading

The deflection criterion of an interface crack under wedge loading was investigated in terms of the ratio of the energy release rate of a deflected crack (Gd) to that of a penetrated crack (Gp), and the virtual crack size (a) was normalized in terms of the length from the interface to the loading point (L). a/L of approximately 0.001–0.05 is required for the deflection criterion (Gd/Gp) to be converged for the composites with Dunders’ parameter α between −0.6 and 0.6.