Numerical investigation on damage behaviour of circular composite laminate under low velocity impact

Low-velocity impact on composite laminates can cause damages such as matrix cracking, delamination, fiber breakage and plastic deformation with large displacements due to accidental drop, resulting in a significant reduction in performance of the laminates. A considerable amount of research is going on worldwide to assess the damage due to such accidental drop and residual life in structures. In this paper, an attempt has been made to study the effect of low-velocity impact on circular CFRP laminated plates numerically using commercially available finite element code LS-DYNA. The numerically simulated results of displacement and absorbed energy are compared with experimental data available in the literature for typical cases and found to have a close correlation within 10%, validating the efficiency of the numerical technique. Parametric investigations in terms of impactor geometry, impact energy, stacking sequence and ply thickness is carried out. Tsai-Wu failure criterion is used to assess the various failure modes based on the failure index and the sequence of failure is established. The permanent deformation, absorbed energy, delamination contour details, sequence of failure as a function of impactor shape, mass and velocity are presented.