Geometrically nonlinear mechanical properties of auxetic double-V microstructures with negative Poisson's ratio

Abstract

Double-V microstructure (DVM) is a type of auxetic cellular material with negative Poisson's ratio (NPR). Accurate predictions of the mechanical properties of these microstructures at large strains are critical for many engineering applications. In this paper, nonlinear theoretical models of two-dimensional (2D) and three-dimensional (3D) DVM based on a large beam deflection model are established to predict the normalized Young's modulus and Poisson's ratio in the principal directions. The theoretical solutions are compared to solutions obtained from numerical finite element analyses and quasi-static compression experiments of a 2D prototype manufactured using additive printing technique. It is found that there is good agreement between these results, validating the accuracy of the proposed theoretical model. Effects of geometry parameters on the mechanical properties of the DVM are also investigated to understand the mechanical behavior at large strains. This study provides validated models for predicting the behavior of these microstructures at large strains, useful for engineering designs.