STRENGTH REDUCTION AND DELAMINATION GROWTH IN THIN AND THICK COMPOSITE PLATES UNDER COMPRESSIVE LOADING

In this paper, the coupled local-global buckling behavior in laminated composite plates with elliptic delaminations and the associated mecha nisms of delamination growth under compressive loads are critically ex amined. The J-integral technique is used for delamination growth predi ction in terms of pointwise energy release rate distribution along the delamination edge. A Multi-plate model, in conjunction with a 3-noded quasi-conforming shell element, is used to model the delaminated plat es. The incremental equilibrium equations are set up based on total La grangian formulation. The solution strategy incorporates Gauss elimina tion in a cycle of Newton-Raphson iterations and is augmented with aut omated are-length controled load incrementation and equilibrium iterat ions; and with automated post-buckling path tracing based on a lineari sed asymptotic solution. The effects of structural parameters such as delamination thickness, size and shape, on the post-buckling behavior and on the delamination growth are critically examined.