Impact damage resistance of CFRP with nanoclay-filled epoxy matrix

The influence of nanoclay on the impact damage resistance of carbon fibre–epoxy composites has been investigated using the low-velocity impact and compression after impact (CAI) tests. The load–energy vs. time relations were analyzed to gain insight into the damage behaviours of the materials. The CFRPs containing organoclay brought about significant improvement in impact damage resistance and damage tolerance in the form of smaller damage area, higher residual strength and higher threshold energy level. The presence of nanoclay in the epoxy matrix induced the transition of failure mechanisms of CFRP laminates during the CAI test, from the brittle buckling mode to more ductile, multi-layer delamination mode. Addition of 3 wt% clay was shown to be an optimal content for the highest damage resistance.