A novel chiral three-dimensional material with negative Poisson's ratio and the equivalent elastic parameters

In this paper, a new kind of chiral three-dimensional honeycomb material was designed by orthogonal assembling based on chiral two-dimensional honeycomb with four ligaments. The analytical formulae of equivalent Young's modulus and Poisson's ratio are deduced using the beam theory. The calculations of the analytical formulae can be well consistent with those of finite element method. The theoretical and numerical results show that the honeycomb material proposed in this paper is isotropic at the macroscopic scale and its Poisson's ratio is close to −1, which means the material have larger ratio of shear modulus to Young's modulus. Furthermore, the influence of geometries on the equivalent elastic parameters are also discussed.