Impact Energy Absorption Analysis of Shape Memory Hybrid Composites

Abstract

Shape memory hybrid composites are hybrid structures with fiber-reinforced-polymer matrix materials. Shape memory wires due to shape memory/super-elastic properties exhibit a pseudo-elastic response with good damping/energy absorption capability. It is expected that the addition of shape memory wires in the glass-fiber-reinforced-polymer matrix composite (GFRP) will improve their mechanical and impact resistant properties. Stainless-steel wires are also expected to improve the impact resistance properties of GFRPs. In this research work, we investigated the effect of addition of shape memory wires and stainless-steel wires on the impact resistance properties of the GFRP and compared our results with conventional GFRPs. Super-elastic shape memory alloy wires and stainless-steel wires were fabricated as meshes and composites were fabricated by the hand-layup process followed by vacuum bagging and the compression molding setup. The shape-memory-alloy-wires-reinforced GFRP showed maximum impact strength followed by stainless-steel-wires-reinforced GFRPs and then conventional GFRPs. The effect of the energy absorption capability of super-elastic NiTi wires owing to their energy hysteresis was attributed to stress-induced martensitic transformation in the isothermal regime above the austenite transformation temperature. The smart shape memory wires and stainless-steel-wires-based hybrid composites were found to improve the impact strength by 13% and 4%, respectively, as compared to the unreinforced GFRPs. The shape-memory-reinforced hybrid composite also dominated in specific strength as compared to stainless-steel-wires-reinforced GFRPs and conventional GFRPs.

Keywords

• shape memory wires
• martensitic transformation
• shape memory hybrid composites
• impact energy absorption