Simulating delamination in composite laminates involving large scale fiber bridging based on the mixed-mode three-linear cohesive zone model

A three-linear cohesive zone model (CZM) superposed by two bilinear laws for modelling mixed-mode delamination with the effect of large scale fiber bridging is proposed in this study. The parameters in the formulation can be obtained from pure mode delamination tests or selected by reliable guidelines, making the CZM easy to be implemented in the finite element model. A novel method to determine the bridging strength by applying varied values in the different regions of the prearranged delamination path is developed. The division of the region is based on the concept of the length of the fracture process zone (FPZ). Simulations of mode I delamination in unidirectional and multidirectional composite laminates and mixed-mode I/II delamination in multidirectional laminate are performed in the finite element analysis software. Good agreement between the predicted load-displacement responses and the corresponding experimental results are achieved by adopting the established CZM and the bridging strength determination method, validating their efficiency in predicting the delamination behaviors under both pure mode and mixed-mode loadings.

Automated summary

This study proposes a novel three-linear cohesive zone model superposed by two bilinear laws for modeling mixed-mode delamination with large scale fiber bridging. A new method to determine bridging strength by applying varied values in different regions of the prearranged delamination path is developed, based on the concept of fracture process zone (FPZ) length. Simulation results show good agreement between predicted load-displacement responses and experimental results, validating the efficiency of the established CZM and bridging strength determination method in predicting delamination behaviors under both pure mode and mixed-mode loadings.