Response and damage due to medium velocity impact on composites

This report describes response and damage of carbon fibre/epoxy composite laminates under medium velocity impact tests. A quasi-isotropic and a wing relevant 3 mm thick layup were tested for each of the materials IM7/8552 and IM7/977-2. Tests were done with an instrumented 10 g impactor at 37 and 47 m/s (7J and 11J). Impact response is expressed by contact load and deflection histories. Damage is quantified by dent depth and size of the delamination zone. The results demonstrate that runway debris may cause significant delaminations without any visible surface damage. Except for a given material and lay-up there was no direct correlation between dent depth and delamination size. Actually, the most severe delaminations were found in the material with the smallest dents.