Revisited criterion to prevent kinking of a crack out of a bi-material interface under the presence of in-plane residual stresses––a global approach

Abstract

Path stability of a crack propagating along an interface between elastically dissimilar layers under the presence of in-plane thermal residual stresses was considered using a numerical analysis. It was predicted that in-plane residual stresses control the energetic conditions to prevent crack kinking out of the interface only through the change in the stress state near the crack tip due to its own contribution to the singular stress field like globally applied loadings. On the other hand, it was predicted that the crack kinking criterion itself, uniquely determined for a given phase angle and a modulus mismatch parameter, is not affected by the residual stress. The numerical results herein suggests that contribution form the residual stress regarding the fracture behaviour of an interface crack is global events and thus supports the assertion elsewhere that fracture process within a K-dominant field can no longer be treated as local problem alone once globally applied residual stress term is involved.