Influence of topology on the impact resistance performance of two-dimensionalchiral negative Poisson's ratio structures

Flexible materials to achieve deformable wing technology requires high mechanical properties of flexible materials，the existing research on chiral structures as flexible materials to drive deformable wings is based on the case of linear small deformations. In order to investigate the mechanical properties of chiral structures under large deformation conditions，five common chiral system negative Poisson's ratio structures，such as tri-chiral，anti-trichiral，tetra-chiral，anti-tetra-chiral，and hex-chiral structures are taken as the object of study. Based on the theory of cellular structural mechanics，the effect of topological structure and cellular element geometrical parameter on the in-plane compression and energy absorption characteristics of chiral system negative Poisson's ratio structures of the intrinsic model of ideal plastic materials are compared and analysed. The results show that the elastic modulus，plateau stress and energy absorption capacity of the chiral structure are inversely proportional to the cell element parameter α and positively proportional to the cell element parameter <i>β</i>. The topology affects the energy-absorbing properties of chiral structures significantly，i.e.，the energy-absorbing capacity of chiral structures with the same single-cell geometrical parameter is significantly enhanced with the increase in the number of ligaments.