Multiple kinking of a tensile crack in the brittle multilayered media abundant with closely-parallel weak interfaces

Abstract

Crack kinking is a basic way to form a complex crack trajectory in a multilayered solid abundant with weak interfaces. However, it remains unclear that under which condition a multi-kinked crack emerges with the influence of closely-parallel weak interfaces. According to a basic crack kink criterion, here we consider a brittle multilayered plate with a tensile edge crack to seek the occurrence condition of the multi-kinking behavior. The strain energy release rate ratio of the crack during its propagation is examined based on finite element simulations. We find a value domain of intersection angle and fracture toughness ratio, where the fracture toughness anisotropy competes with the load anisotropy to orient the crack propagation direction. We obtain the continual kinking condition of the tensile edge crack, including the intersection angle range about 0∼38° and the closed form upper and lower bounds of the fracture toughness ratio range. Our multi-kinking results for the tensile crack are helpful to understand the formation of complex crack patterns in the multilayered materials under complicated loads.