Buckling and delamination growth behavior of composite laminates with circular initial delamination

In this paper, the sub-laminate local buckling, global buckling and delamination propagation behavior of composite laminates with circular embedded delamination were studied numerically. First, linear buckling analyses were performed and buckling loads and modes of local sub-laminate and global buckling were identified. Next, geometrically nonlinear post-buckling and delamination propagation analyses were performed. Buckling deformation was instigated by seeding finite element meshes with a small amount of combined linear buckling modes. In-plane failure and interface delamination were accounted for by a continuum damage mechanics method and cohesive zone modeling, respectively. Analyses were performed to investigate the interaction between local sub-laminate buckling, global buckling, in-plane failure, and delamination propagation. The dependence of buckling behavior on the size and depth of location of pre-delamination was also investigated by a series of parametric studies.