Origami-inspired highly impact-resistant metamaterial with loading-associated mechanism and localization mitigation

Abstract

Breakthroughs in highly impact-resistant materials and structures are crucial in engineering fields such as military protection, transportation and architecture. Nevertheless, the resisting efficiency of conventional materials has progressively fallen short of increasing advanced engineering demands. In this study, drawing inspiration from the flexibility and versatility of cutting-edge origami design, a novel metamaterial with enhanced impact resistance capabilities is proposed. The core principle of microstructural design is based on origami kinematics, where the constrained degrees of freedom create interrelated movements and deformations across various components. It gives a triaxial loading-associated energy absorption mechanism where the periodic units of the metamaterial exhibit strong resistance and high internal forces in all directions when subjected to any uniaxial load, resulting in more extensive deformation and strain localization mitigation. For further mechanism analysis, an origami metamaterial specimen is fabricated using Selective Laser Melting (SLM) 3D printing technology with 6061 aluminum alloy. A light-gas gun system is used for the test of specimen impact resistance, resisting high-kinetic-energy projectile above 500J. A corresponding simulation model is also constructed to investigate the impact behavior. The results demonstrate that the origami metamaterial exhibits exceptional impact resistance, e.g., higher ballistic limit and higher specific energy absorption (SEA). Overall, this work reveals a high impact energy absorption mechanism based on origami kinematics, which further contributes to the mechanistic interdisciplinary study of origami geometry and impact dynamics.