Finite element modelling of mixed-mode delamination propagation in Abaqus/Explicit with linear and nonlinear cohesive softening laws

Accurate modelling of delamination propagation in laminates is key to predicting the failure of composite structures. In this study, an implementation of the Cohesive Zone Model (CZM) using a novel mixed-mode formulation based on defining an effective separation and allowing for generalizable non-linear cohesive traction-separation softening laws, is presented and evaluated. To this end, several finite element models representing a laminate specimenunder puremode I, puremode II, ormixed-mode conditions, respectively, are constructed and benchmarked against other studies from literature. Then, the influence of the cohesive softening law shapes on the load-displacement response of the specimen is evaluated. Results show that, with the appropriate softening law shape, the novel implementation successfully captures delamination growth and most load-displacement characteristics without the need for an empirical energy criterion.