In-plane characteristics of a multi-arc re-entrant auxetic honeycomb with enhanced negative Poisson's ratio effect and energy absorption

Based on conventional re-entrant auxetic honeycomb (CRAH), a multi-arc re-entrant auxetic honeycomb (MARAH) is proposed. The mechanical properties of the honeycomb can be significantly improved by introducing multiple arcs. Through theoretical analysis, finite element analysis, and experiment, the influence of arc radius, arc angle, and cell wall thickness on effective Poisson's ratio, effective Young's modulus, energy absorption, and stress level are investigated. There are significant differences between MARAH and CRAH in Poisson's ratio, deformation mode, stress level, and energy absorption. Compared with CRAH, MARAH has a better negative Poisson's ratio effect, wider Poisson's ratio adjustable range, better energy absorption, and superior stability. In addition, the reduction of the yield stress can effectively reduce the damage of impact load on the honeycomb. The research results can provide new ideas for the design and application of new metamaterials.