Postbuckling behavior of composite plates with through-the-width delaminations

Fiber-reinforced composite materials have been increasingly used over the past few decades in a variety of applications in which a fairly high ratio of stiffness/strength to weight is required. However, these materials are prone to a wide range of defects and damage that can cause significant reductions in stiffness and strength. Delamination is one of the most common failure modes in composite materials which affect the overall stiffness of the structure. In this paper, the compressive behavior of composite laminates with through-the-width delaminations is investigated analytically. The analytical method is based on the CLPT theory, and its formulation is developed on the basis of the Rayleigh–Ritz approximation technique to analyze the bucking and postbuckling behavior of delaminated laminates. The method can handle both local buckling of the delaminated sublaminate and global buckling of the whole plate. Also the three-dimensional finite element analysis is performed by using ANSYS5.4 general purpose commercial software, and the results are compared with those obtained by the analytical model. The agreement between the results is very good.