Impact damage characteristics and post-impact compressive properties of Z-reinforcement foam core sandwich composites

Resin column reinforced, carbon fiber prepreg bar reinforced and kevlar fiber stitched reinforced foam core sandwich composites were produced using the same face sheets based on the autoclave manufacturing technology. The prepared sandwich structures were tested under low-velocity impact and post-impact compression. The post-impact damage characteristics and damage modes were also studied. The results indicate that initial damage of foam-core is caused by the Z-reinforcement, and the post-impact damage area increases compared with that of the unreinforced one, while the compressive failure mechanism of foam core sandwich composites is changed by the Z-reinforcement. The compressive strength and the CAI strength can be improved by choosing the right Z-reinforcement material and parameter, which increase by 13% and more than 40% respectively with carbon fiber prepreg bar reinforced at 10 mm?10 mm Z-reinforcement parameters.