Experimental and Numerical Investigation of Energy Absorption in Auxetic Structures under Quasi-static Loading

Human being has always been looking for optimal use of his surrounding materials that has been able to invent various structures through getting inspired by nature. Some of these structures are lattice structures. Due to their lower weight, high compressive strength and high stiffness, lattice structures are widely used in various applications, including energy absorbers. A new type of lattice structure is auxetic structures that have a negative Poisson’s ratio due to their geometric structure. This characteristic has caused auxetic structures to have unique properties such as shear strength, indentation resistance, and high-energy absorption. In this study, the experimental and numerical investigation of in-plane uniaxial quasi-static loading on three auxetic structures and one non-auxetic structure have been conducted. The specimens have three different auxetic geometries including re-entrant, arrowhead and anti-tetra chiral and one honeycomb geometry that is non-auxetic. The specimens have been manufactured using additive manufacturing technology (3D printing). Experimental results were compared with finite element simulation results, which were in a good agreement. As expected, auxetic structures showed a much better performance in energy absorption compared to the honeycomb structure. So that the energy absorption of the arrowhead structure was 161% higher than the honeycomb structure.