In-plane elasticity of a novel vertical strut combined re-entrant honeycomb structure with negative Poisson’s ratio

Abstract In this study, a new vertical strut combined re-entrant auxetic structure was designed and its mechanical behaviors have been studied. An analytical model was established based on energy theorems considering bending, shearing and stretching. Numerical simulations and experiments were both carried out to confirm the validity of the analytical model based on beam theory. Results exhibited a good agreement between the refined analytical model, the numerical simulation and experimental study. Four deformation mechanisms were analyzed and the effect of deformation on the effective Poisson’s ratio (EPR) and elastic module were investigated. A parametric study was further performed to quantitatively illustrate the influences of the geometrical parameters on the effective elasticity properties of the designed structure. The results showed that the lightweight structures can significantly enhance the auxetic behavior and achieve a high degree of anisotropy with wide vertical strut lengths and internal angles compared with conventional re-entrant honeycomb configurations.