Deformation features of the two-dimensional mechanical tetrachiral metamaterial

Abstract

The paper deals with a 2D metamaterial constructed from chiral elements comprising rings and ligaments (ribs). The behavior of the metamaterial during tension was studied by numerical modeling. The shear deformation appears within the tetrachiral honeycomb under uniaxial loading. It is found that coupling exists between the elongation and inclination of the sample with tetrachiral honeycomb structure and this causes some ambiguity when calculating the effective Poisson's ratio. The coupling effect depends on both the honeycomb's deformation and the geometric parameters of the cell structure. This special coupling effect of tetrachiral honeycombs provides a new idea for designing new metamaterials. An analytical expression for this effective Poisson's ratio is derived. In the process of uniaxial loading, the reason for the elongation of the specimen was found.