In this study, buckling and postbuckling analysis was conducted for the composite laminated panels 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 arc-length method were adopted. For a finite element modeling of composite laminates, the eight-node degenerated shell element was used. To avoid the overlapping between delaminated layers, the contact node pairs were defined by virtual beam element. For the verification of this finite element modeling, the experiments of the unidirectional laminates with artificially inserted delaminations were performed. 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.
