Numerical investigation into multi-delamination failure of composite T-piece specimens under mixed mode loading using a modified cohesive model

This paper investigated the failure mechanism of fibre composite T-piece specimens under mixed mode loading conditions by simulation of multi-delamination using a modified cohesive model with a coupled damage scale and added thermal effects. A mixed mode load includes pulling and bending. Multi-delamination was simulated in the way modelling the dominated multi-delamination in the deltoid region of T-piece. Failure predictions in the mixed mode loading case, individual bending and pulling case together with part of tested solutions were presented in this paper. It was exposed that the interaction between pulling and bending in the mixed mode loading case plays an important role in the failure mechanism of T-piece. The effect of thermal initial crack in the deltoid of T-piece on prediction of the capacity to resist mixed mode loading was also investigated. A significant effect of thermal initial crack on delamination was found in the mixed mode loading case. This investigation supplied important information for the design of T-piece related composite components under mixed mode loading conditions.