COMPRESSIVE FAILURE BEHAVIOR OF COMPOSITE LAMINATES AFTER LOW VELOCITY IMPACT

Compressive failure tests were carried out on composite laminates and stitched laminates after low velocity impact to study compressive failure mechanisms of laminates after low velocity impact. Methods of X-ray, C-scan, deply, etc were used to measure and to record the internal and external damage of the laminates. The implications of this study were that sub-laminate buckling and the delamination expending were the important factors causing large reductions in strength while CFRP laminates were compressed after low velocity impact if the interface properties were not very fine. And the buckling area expended mainly in the direction perpendicular to the compressive load. For quasi-isotropic composite laminates, the orientation of the ply in buckled sub-laminate next to parent medium was generally 90°. There was no direct relation between residual compressive strength and impact damage area.