The Nonlinear Compressive Response and Deformation of an Auxetic Cellular Structure under In-Plane Loading

The nonlinear compressive response and deformation of an auxetic cellular structure that has periodic negative Poisson's ratio (NPR) cell were studied through theoretical and numerical method. The in-plane deformation and process of absorbing energy of this NPR cellular structure were discussed. The relative density of NPR cell was determined by geometric parameters and a theoretical approach to the strength of NPR cell was carried out to analyze the failure process under in-plane compression. Thus, to prove the effective of unit cell mechanical model, the size effect of this NPR cellular structure was discussed. The simulations of two different NPR cellular structures under in-plane compression were generated and their effective properties, strain-stress curves, and absorbed energy were analyzed. It can be concluded that the NPR cell that has lower relative density may have better capability of absorbing energy with enhanced Young's modulus. Finally the parametric analyses related to relative density were presented with NPR unit cell model and a set of quasistatic compressive experiments was carried out, which can be used to reveal the nonlinear properties of NPR cellular structure and to prove the effectiveness of theoretical method.