Design and mechanical properties of 3D-printed auxetic honeycomb structure

The combination of theoretical calculations, computer simulations, and experimental evaluation of Poisson's ratio was carried out for re-entrant honeycomb auxetic structure. Optimal honeycomb cell parameters were determined for 3D-printed samples made from thermoplastic polyurethane (TPU). The low-cycle compression tests of 3D-printed re-entrant honeycomb auxetic samples showed that the structure based on auxetic hexagonal cell can withstand almost 1.75 times more very low cycle fatigue cycles than the similar non-auxetic structure. Neither failure nor layer delamination in 3D structures were detected in the auxetic sample after 500 compression cycles. 3D-printed auxetic structures offer a promising candidate for applications in medicine and sports.