Study of the Effect of Viscous Filler on the Penetrating of Auxetic and Non-Auxetic Metamaterials

The properties of metamaterials with negative and positive Poisson’s ratio (with an auxetic structure based on a cell in the form of a concave hexagon or a conventional honeycomb structure of convex hexagons) to resist penetration by a rigid spherical striker along the normal have been experimentally studied. Samples of metamaterials, including those with a chiral structure, are made of e‑PLA plastic using a 3D printer. Auxetic and non-auxetic samples, approximately equal in mass, have been compared by their ability to reduce the kinetic energy of penetrating strikers in conditions of cells filled with air and gelatin. We have established a fact of a significant increase in penetration resistance when auxetic chiral samples are filled with gelatin compared to those filled with chiral non-auxetics. In experiments with chiral metamaterials filled with gelatin, a deviation of the striker motion direction after leaving the sample being penetrated from the approach direction (normal to the side surface) has been recorded.