Analysis of post-buckling and delamination in laminated composite St. Venant-Kirchhoff beams using CZM and layer-wise TSNDT

摘要

A layer-wise third order shear and normal deformable plate/shell theory (TSNDT) incorporating a cohesive zone model (CZM) is used to study the initiation and growth of delamination in straight and curved laminated beams. Upon satisfaction of the delamination criteria at a point on the interface between two layers, displacements there of two abutting points on the interface between the two layers are made discontinuous. Delaminations under mode-1, mode-II and mixed-mode static and transient loadings have been studied. All geometric nonlinearities, including the von Karman nonlinearity, are considered. The material of each layer is assumed to be St. Venant-Kirchhoff for which the second Piola-Kirchhoff stress tensor is a linear function of the Green-St. Venant strain tensor. Example problems studied also include delamination growth during axial buckling of a three-layer beam. It is found that the consideration of inertia forces noticeably delays the buckling load and significantly affects the deformed shape of an axi-ally compressed laminated beam.