Damage evaluation of repeated impact events on glass/carbon hybrid composites

Drop-weight experiments studied the damages due to repeated low-velocity impacts of hybrid composite laminates. The laminate made by carbon woven fabric and glass woven fabric impregnated by vinyl ester resin was subjected at single impact, at 5 repeated impacts and 10 repeated impacts, for an energetic level of U=20J. The final damage after the single and repeated impact events was analysed by no-destructive methods, Pulse Thermography and Holographic Interferometry to evaluate the influence of the multi-hit events on the damaged area's evolution.