Low velocity impact of a recoverable multistable mechanical metamaterial with negative stiffness elements

Materials and structures absorbing shock energy are crucial for diverse engineering applications. Conventional materials or structures absorb energy through material destruction or viscoelastic effect, resulting in systems that can be used only once or strongly rate-dependent. Very recently, mechanical metamaterials have been designed in novel geometrics to achieve recoverable energy absorption in elastic systems, opening new avenue for mechanical dissipation of energy. However, numerical modeling of impact response of this mechanical materials is really scarce. Here we build a finite element method (FEM) model of a mechanical metamaterial with negative stiffness elements to simulate the quasi-static and low velocity impact behavior. Quasi-static simulation results agree well with experimental results reported in literature, and low velocity impact results indicate this mechanical metamaterial with multistable negative stiffness elements is ideal for impact energy absorption.