Curve beam for strengthening the negative Poisson's ratio effect of rotating auxetic metamaterial: Experiments and simulations

Abstract

This article described a three-dimensional lattice design method for customizing the negative Poisson’s ratio effect in a rotating rigid structure. By using bent beams as the basic building blocks of the lattice, a new class of curved beam rotating auxetic (CBRA) lattice was proposed. Through a combination of numerical simulations and experimental tests, the mechanical responses of representative three-dimensional auxetic lattice structures under compressive load were systematically studied, including Poisson’s ratio, energy absorption, and a multi-stage deformation mode that facilitated the tuning of mechanical properties. Additionally, the influence of structural geometric parameters on the elastic performance was discussed in detail. Unlike most rotating auxetic materials that could only achieve the negative Poisson’s ratio effect within a small strain range, the results demonstrated that the uniform Poisson’s ratio of the proposed three-dimensional lattice structure could achieve positive and negative adjustment within a strain range of 0–0.5. The design flexibility would contribute to making it a promising candidate for industrial and biomedical applications, such as scaffolds and skin grafts. The acceleration of the application of new three-dimensional expandable lattice structures in engineering applications made this system more versatile than similar non-graded systems.