A 3D Star-Shaped zero Poisson’s Ratio Honeycomb with Cubic Symmetry

A three-dimensional (3D) star-shaped zero Poisson’s ratio (ZPR) honeycomb with cubic symmetry is proposed in this paper based on a twodimensional (2D) star-shaped ZPR honeycomb. Based on the Timoshenko beam theory and the energy method, the analytical formulas for the equivalent Young’s modulus and the specific stiffness of the new honeycomb are obtained, which are verified by the numerical analysis and the experiments. The results show that the proposed new honeycomb has the ZPR effect in all three principal directions with the same equivalent Young’s modulus. With this excellent property, the novel honeycomb is of good application prospect in some important fields, such as anti-collision facilities and wing morphing. In addition, the influence of the geometric parameters on this new honeycomb’s elastic performance is further studied. The results show that the new honeycomb’s elastic performance can be significantly improved by increasing either the thin struts’ slant angle or the ratio of width to height of the thin struts. This study provides a new idea for the design of 3D ZPR honeycombs.

Keywords: Zero Poisson’s ratio (ZPR); Equivalent parameters; Timoshenko beam theory; Three dimensional (3D); Star-shaped honeycomb