Mechanical behavior of dumbbell-type metamaterials constructed with elliptic curves

Abstract

In this paper, based on the traditional concave ortho-hexagonal honeycomb (CHH), its curvilinear modified design was introduced into the elliptic curve configuration, and a novel dumbbell-shaped honeycomb (DH) was proposed. All specimens were prepared by Liquid Crystal Display (LCD) light-cured 3D printing. The aim of this study is to investigate the deformation and damage behavior and mechanical properties of DH and CHH under in-plane quasi-static uniaxial compression and tension. The effects of variation of the cell parameters semi-major axis length a and semi-minor axis length b on the deformation, damage behavior and mechanical properties of DH have been investigated. The experimental results show that the DH incorporating the elliptical curvilinear design has a reduced internal compressive strength under compression, but the negative Poisson’s ratio property is enhanced, which is 17% higher compared to the CHH, and the tensile strength under tension is reduced compared to the CHH, but the tensile ultimate strain is increased by 25% compared to the CHH. This will help to improve the problem of stress concentration and negative Poisson’s ratio in the process of deformation of conventional structures. Differences in the a and b parameters in the DH structure will have different effects on its deformation-fracture behavior and mechanical properties.