Impact resistance of a double re-entrant negative poisson's ratio honeycomb structure

Auxetic metamaterials, usually consisting of cellular solids or honeycombs, exhibit the advantages of high designability and tunability. In particular, the negative Poisson's ratio (NPR) property endows them with innovative mechanical properties and makes them promising for a wide range of applications. This paper proposes a modified double re-entrant honeycomb (MDRH) structure and explores its Young's modulus and Poisson's ratio through theoretical derivation and finite element analysis. Additionally, it discusses the relationship between these parameters and the concave angle. Furthermore, the deformation mode, nominal stress-strain curve, and specific energy absorption of this MDRH are investigated for different impact velocities and compared with traditional re-entrant honeycomb (TRH) materials. The results show that the MDRH honeycomb structure greatly widens the range of effective modulus and NPR values. At different impact velocities, the MDRH exhibits high plateau stress and specific energy absorption, indicating good impact resistance. These results provide a theoretical foundation for the design and implementation of new energy-absorbing structures.