Failure analysis of laminated composite cylindrical/spherical shell panels subjected to low-velocity impact

A 4-noded, 48 d.o.f. doubly curved quadrilateral shell finite element based on Kirchhoff-Love shell theory, is used in the nonlinear finite element analysis to predict the damage of laminated composite cylindrical/spherical shell panels subjected to low-velocity impact. The large displacement stiffness matrix is formed using Green's strain tensor based on total Lagrangian approach. An incremental/iterative scheme is used for solving resulting nonlinear algebraic failure criterion at all Gauss points and the mode of failure is identified using maximum stress criteria. The nodes of failure considered are fiber breakage and matrix cracking. The load due to low-velocity impact is treated as an equivalent quasi-static load an Hertzian law of contact is used for finding the maximum contact force. After evaluating the nonlinear finite element analysis thoroughly for typical problems, damage analysis carried out the cross-ply and quasi-isotropic cylindrial/spherical shell. (C) 1998 Elsevier Science Ltd. All rights reserved.