Impact resistance of Z-pin-reinforced sandwich composites

This study investigates the effect of face materials, Z-pin types and distribution densities on drop-weight impact properties of foam core sandwich composites. The novelty of this study is to eliminate damage of face part by only reinforcing the core part of sandwich structures. Impact test was performed at different energy levels (20-50 J). The addition of Z-pins into the sandwich composites decreased the elasticity and ductility while it increased the stiffness of sandwich composites. The Z-pin reinforcement increased the peak forces, but decreased the peak deformations of the sandwich composites. However, higher energy absorption was only observed at the higher Z-pin distribution density. The results showed that Z-pin distribution density, bonding between the face sheets/pins, and the face sheet material have a great influence on the impact behaviour of the Z-pin-reinforced sandwich composites besides the Z-pin types.