An enriched cohesive zone model for numerical simulation of interfacial delamination in microsystems

Interfacial failure, mainly in the form of debonding or delamination of brittle interfaces, is one of the major sources of failure in microsystems that consist of multiple thin and stacked layers, manufactured using different materials. A cohesive zone model with a simple traction- separation law is employed to simulate the benchmark test of pure mode I delamination in a double cantilever beam. A local arc-length control procedure is also detailed and its robustness is shown in the case that the quasi-static solution contains limit points due to the brittle nature of the interface considered here. Finally, a bilinear hierarchical extension is proposed to enhance the efficiency and robustness of cohesive zone models by enriching the separation approximation in the process zone of a cohesive crack in brittle interfaces without need for further mesh refinement.