Kinking angles for interface cracks

Bi-material components such as ceramic/ceramic or silicon/glass bonds are used extensively in different industrial applications. The presence of cracks in the interface of such bonded joints influences their mechanical strength significantly. For strong interfaces, cracks sometimes kink out of the interface and then extend in one of the two materials. In this paper, a fracture criterion is developed for predicting the kinking angle in the interface cracks between two dissimilar isotropic elastic solids. The criterion takes into account the effect of T-stress in addition to the stress intensity factors KI and KII. It is shown that the suggested criterion provides very good estimates for some experimental results reported in earlier papers for interface cracks.