Metamaterial for Crashworthiness Applications

Metamaterials are artificial lattice structures or man-made cellular materials with unique mechanical, thermal, optical, and electromagnetic properties enabling their adoption for a wide range of engineering applications. The macroscopic performance of such metamaterials is dominated by the geometrical configuration of their respective unit cell which is normally engineered at microscale or nanoscale. These novel materials have attracted increased research interests as they offer a set of characteristics and functionalities that cannot normally be realized in conventional materials. High strength-to-density ratio and excellent energy absorption capabilities are among the properties exhibited by these materials making them ideal candidates for crashworthiness applications in automotive, aerospace, and defense engineering sectors. This article aims to review the recent developments concerning the energy absorption and impact responses of the metamaterials. An overview of the mechanical properties and manufacturing techniques of metamaterials is first introduced and then the recent studies on the energy absorption performance of metamaterials under dynamic and quasi-static loading are highlighted.