Due to the unique deformation characteristics of auxetic materials (Poisson’s ratio ), they have better shock resistance and energy absorption properties than traditional materials. Inspired by the concept of variable cross-section design, a new auxetic re-entrant honeycomb structure is designed in this study. The detailed design method of re-entrant honeycomb with variable cross-section (VCRH) is provided, and five VCRH structures with the same relative density and different cross-section change rates are proposed. The in-plane impact resistance and energy absorption abilities of VCRH under constant velocity are investigated by ABAQUS/EXPLICIT. The results show that the introduction of variable cross-section design can effectively improve the impact resistance and energy absorption abilities of auxetic re-entrant honeycombs. The VCRH structure has better Young’s modulus, plateau stress, and specific energy absorption (SEA) than traditional re-entrant honeycomb (RH). The influence of microstructure parameters (such as cross-section change rate ) on the dynamic impact performance of VCRH is also studied. Results show that, with the increase in impact velocity and , the plateau stress and SEA of VCRH increase. A positive correlation is also found between the energy absorption efficiency, impact load uniformity and under both medium and high impact speeds. These results can provide a reference for designing improved auxetic re-entrant honeycomb structures.

Auxetic re-entrant honeycombs; variable cross-section design; in-plane impact; finite element simulation