A cohesive finite element formulation for modelling fracture and delamination in solids

In recent years, cohesive zone models have been employed to simulate fractu re and delamination in solids. This paper presents in detail the formulatio n for incorporating cohesive zone models within the framework of a large de formation finite element procedure. A special Ritz-finite element technique is employed to control nodal instabilities that may arise when the cohesiv e elements experience material softening and lose their stress carrying cap acity. A few simple problems are presented to validate the implementation o f the cohesive element formulation and to demonstrate the robustness of the Ritz solution method. Finally quasi-static crack growth along the interfac e in an adhesively bonded system is simulated employing the cohesive zone m odel. The crack growth resistance curves obtained from the simulations show trends similar to those observed in experimental studies.