Buckling and postbuckling behavior of composite cross-ply laminates with multiple delaminations

Abstract

In this study, buckling and postbuckling analysis was conducted for the composite cross-ply laminates with multiple delaminations under compressive loading. The geometries of multiple delaminations are a one-dimensional through-the-width type and a two-dimensional embedded circular type. In a nonlinear finite element formulation, the updated Lagrangian description and the modified are-length method were adopted. For a finite element modeling of composite laminates, the eight-node degenerated shell element was used. To avoid overlapping between delaminated areas, the contact node pair was defined by virtual beam element. Numerical results showed that multiple delaminations lower buckling loads and load carrying capacities in the postbuckling region. The buckling load varies with the projected area of the delaminations, However, the geometry of multiple delaminations has an influence on the postbuckling behavior. The load carrying capacity differed with the distribution type due to the local reduction of bending stiffness and the contact behavior of the sublaminates.