A Damage Model Reflecting the Interaction between Delamination and Intralaminar Crack for Failure Analysis of FRP Laminates

In this paper, a progressive damage model reflecting the interaction between delamination and intralaminar crack is developed to predict fracture behaviors and the ultimate load-bearing ability of the fiber-reinforced polymer laminates subject to quasi-static load. Initiation and evolution of intralaminar crack in composites are modeled using a continuum damage mechanics model, which has the capability to reliably predict the discrete crack direction by introducing the crack direction parameter while analyzing the multi-failure of FRP composites. Delamination is modeled using a cohesive zone method with the mixed bilinear law. When the continuum damage model and cohesive zone model are used together, the interactive behavior between multiple failure mechanisms such as delamination induced by matrix cracking often seen in the failure of composite laminates is not generally captured. Interaction between delamination and intralaminar crack in FRP composite structures is investigated in detail and reflected in a finite element analysis in order to eliminate the drawbacks of using both models together. Good agreements between numerical results and experimental data are obtained.