An enriched cohesive zone model for delamination in brittle interfaces

Application of standard cohesive zone models in a finite element framework to simulate delamination in brittle interfaces may trigger non-smooth load-displacement responses that lead to the failure of iterative solution procedures. This non-smoothness is an artifact of the discretization; and hence it can be avoided by sufficiently refining the mesh leading to unacceptably high computational costs and a low efficiency and robustness. In this paper, a process-driven hierarchical extension is proposed to enrich the separation approximation in the process zone of a cohesive crack. Some numerical examples show that instead of mesh refinement, a more efficient enriched formulation can be used to prevent a non-smooth solution.