Deflection criterion of a crack approaching a bi-material interface obliquely

Deflection criterion for oblique cracks terminating at a bi-material interface was established numerically based on a remote loading condition where the crack deflection event took place well within the K-dominant stress field. The criterion was described in terms of the ratio of the energy release rate of a deflected crack (G(d)) to the maximum energy release rate of a penetrated crack (G(p)(max)). The criterion was markedly more conservative than the existing solution based on wedge loading which did not converge with respect to limited number of a/L ratios in the literature (a is the size of the putative crack; L is the loading distance). Further, the criterion established herein for the cracks slightly oblique from the normal direction to the interface was more conservative than the crack normal to the interface.