Effect of Strain Dependent Cohesive Zone Model on Predictions of Interface Crack Growth

Crack growth along an interface joining an elastic-plastic solid to a solid that does not yield plastically is studied numerically, accounting for mixed mode loading under conditions of small scale yielding. The fracture process is represented in terms of a cohesive zone model, for which the work of separation per unit area and the peak stress required for separation are basic parameters; but where also a plastic strain effect on the fracture process is incorporated. This additional effect is included to model accelerated void nucleation and growth at the interface, resulting from intense plastic straining just in front of the crack tip.