Finite Element Analysis of Single-Leg Bending Delamination of Composite Laminates Using a Nonlinear Cohesive Model

Delamination is a dominating failure mechanism in composites. Deep insight into mixed-mode delamination failure mechanism requires advanced numerical methods. Currently, the cohesive zone model (CZM) by combining with the finite element analysis has become a powerful tool for modeling the delamination initiation and growth of composites. Based on the middle-plane interpolation technique, this paper first develops a 3D finite element technique for implementing exponential CZM using ABAQUS-UEL (User element subroutine). Then, the effects of the cohesive strength, mesh size and initial delamination crack length on the delamination behavior and load response for two single-leg bending composite specimens with mixed-mode I/II delamination modes are studied by comparison with the experimental results. In addition, the viscous effect on the load–displacement curves for two specimens is also studied.