Hyperelastic-elastoplastic composite metamaterials for reusable energy absorption

Abstract High-performance and reusable energy-absorbing materials hold significant promise for industrial applications. However, their relatively low specific energy absorption capacity has impeded their advancement. Balancing high performance with reusability has posed significant challenge in this field. This paper innovatively proposes hyperelastic-elastoplastic composite metamaterial that cleverly integrates liquid metal into an elastic hollow lattice structure through a molding process. This type of metamaterial demonstrates exceptional mechanical properties and substantial energy absorption capabilities when the liquid metal is in its solid state, primarily leveraging the plastic deformation to efficiently absorb energy. Upon heating, the solid–liquid phase transition is initiated, and the elastic shell facilitates a fully reversible deformation, thereby ensuring the reusability. This paper investigates the performance characteristics of hyperelastic-elastoplastic composite metamaterials fabricated with various liquid metals, including gallium (Ga) and Wood’s alloy. Additionally, the potential applications of this metamaterial are discussed, highlighting its extensive value across diverse industrial scenarios.