INDENTATION-FLEXURE AND LOW-VELOCITY IMPACT DAMAGE IN GRAPHITE-EPOXY LAMINATES

Static indentation-flexure and low-velocity impact tests were performe d on quasi-isotropic and cross-ply graphite/epoxy composite laminates. The load-deflection relations in static tests and impact force histor y in impact tests were recorded. The damage was assessed by using ultr asonic C-scanning and photo-micrographic techniques. Some features of the static behavior were explained by simple analytical models. A good correlation existed between the load-deflection curves for static and impact loading. It was found that results from a few static indentati on-flexure tests can be used to predict the impact force history and d elamination radius in composite laminates due to low-velocity impact.