Design and elastic mechanical response of a novel 3D-printed hexa-chiral helical structure with negative Poisson’s ratio

Abstract

Nowadays, the development of 3D-printing technology makes it possible for fabricating metamaterials with distinctive mechanical properties. In this paper, we present a novel design of 3D hexa-chiral helical structure with negative Poisson’s ratio and systematically study its mechanical behaviors through experimental, theoretical, and numerical methods. In terms of structural design, besides geometric configurations, we propose a theoretical model to qualitatively analyze the relationship between geometric parameters and structural properties. For actual mechanical properties, an approximate method is presented to decouple the structural deformation based on marks’ displacements. With the assistance of quasi-static compression tests and finite element simulation, the relationship between geometric parameters and elastic mechanical properties is studied. The experimental results are in good agreement with the simulation results. Meanwhile, the special coupled compression-torsion deformation mode is also discussed. Finally, we briefly study the extension effect of the structure in a larger space through numerical simulations. These results are helpful to further optimize the geometric design for customized structural performance to a certain degree.