Mechanical Properties of Star-Shaped Gradient Lattice Structures Under Tensile Load

Abstract

Star-shaped lattice structures with a negative Poisson’s ratio (NPR) effect exhibit excellent energy absorption capacity, making them highly promising for applications in aerospace, vehicles, and civil protection. While previous research has primarily focused on single-walled cells, there is limited investigation into negative Poisson’s ratio structures with nested multi-walled cells. This study designed three star-shaped cell structures and three lattice configurations, analyzing the Poisson’s ratio, stress–strain relationship, and energy absorption capacity through tensile experiments and finite element simulations. Among the single structures, the star-shaped configuration r3 demonstrated the best elastic modulus, NPR effect, and energy absorption effect. In contrast, the uniform lattice structure R3 exhibited the highest tensile strength and energy absorption capacity. Additionally, the stress intensity and energy absorption of gradient structures increased with the number of layers. This study aims to provide a theoretical reference for the application of NPR materials in safety protection across civil and vehicle engineering, as well as other fields.