Effects of non-planarity on the mixed mode fracture resistance of bimaterial interfaces

The effects of non-planarity on the fracture resistance locus of interfaces has been investigated using a simple model of contacting facets along the crack surface. The contacts resist the motion of the crack surface by means of friction and locking and thereby modify the energy release rate G t at the crack front. The modified G t governs the effect of the contacting facets on the overall interface fracture resistance, G j . The trends in G j with phase angle of loading are found to be influenced largely by a non-dimensional parameter that determines the length of the contact zone. This parameter is, in turn, dependent on the amplitude of the undulations on the fracture interface as well as its intrinsic fracture resistance.