A ply-by-ply discretized 2D FEA approach with the integrated XFEM-CE strategy for predicting multiple failures in laminated composite structures

Delamination and matrix cracking are two common failure mechanisms in composite structures, and are usually coupled with each other, leading to multiple failures pattern. This paper proposed a fast damage prediction methodology for composite laminated structures based on the ply-by-ply 2D (two dimensional) FE model of composite laminates in the transverse plane. The layer-wise 2D FE model was firstly used in conjunction with the integrated XFEM/CE strategy, which simulated the interface delamination with cohesive elements and the intra-ply matrix crack with XFEM (extended finite element method). To realize ply-by-ply 2D FE (finite element) modeling of composite laminates, two 2D material models were developed based on the plane stress assumption and plane strain assumption, respectively. A general crack propagation scheme was developed in the framework of the integrated XFEM-CE method. Adopting the 2D material model based on the plane strain assumption, a ply-by-ply discretized 2D FEA procedure was conducted for an out-of-plane composite Pi joint under the static tensile load. The predicted load-displacement response and damage evolution process showed good agreement with the experimental results, which verified the proposed approach.