On the Influence of Temperature of Flexible Auxetic Metamaterials on The Energy Loss of a Striker During Penetration

Abstract The resistance of auxetic metamaterial samples manufactured on a 3D printer from flexible thermoplastic polyurethane (TPU 95A plastic) based on a cell in the form of a concave hexagon (metamaterials with negative Poisson’s ratio) to penetration by a rigid spherical striker along the normal was experimentally studied. Samples were prepared whose internal structure differed in the angle of rotation (0, 30, 45, 60, or 90 degrees) relative to the vertical axis. The samples were compared for their ability to reduce the kinetic energy of strikers at a velocity of approximately 190 m/s at temperatures of 5, 16, 25, and 35°C. It was found that, in the examined temperature range, the samples most effectively resist penetration by a striker at 25°C. Moreover, for all temperatures, the highest resistance is characteristic of auxetic metamaterials made of thermoplastic polyurethane, with a structure rotated by 90 degrees.