In-plane compression behavior of meta-tetrachiral and common auxetic structures

Meta-tetrachiral structure, as a novel negative Poisson's ratio auxetic materials, combines the topological features of tetrachiral and anti-tetrachiral structures. Under the in-plane compression, a comparative study on the mechanical properties of the meta-tetrachiral and the common tetrachiral and anti-tetrachiral structures is investigated experimentally and numerically. Three types of specimens are fabricated by using Stereo Lithography Apparatus (SLA) technology; numerical models are established by using FEA software and verified by quasi-static compression tests. The simulated and experimental results together indicate that the in-plane deformation patterns of the meta-tetrachiral are limited by the different loading directions. The deformation mechanism of the meta-tetrachiral loaded along different directions is summarized by the deformation behavior of the specimens. The Young's modulus of the meta-tetrachiral loaded along different directions is larger than that of the anti-tetrachiral structure. The auxetic properties (NPR) of the meta-tetrachiral structures loaded along different directions are superior to that of the tetrachiral structure. In addition, it is found that the meta-tetrachiral loaded along the Y-direction shows a better performance in terms of energy absorption compared to the other structures. The effect of the meta-tetrachiral structures with different wall thicknesses on energy absorption was investigated.