Abstract
Abstract
Metamaterials are a promising solution to meet the increasing demand for high-performance materials that are also lightweight. A key feature of many metamaterials is their negative Poisson’s ratio, which leads to counterintuitive deformation behavior during mechanical stress. This property is unaffected by scale, making it both a macroscopic material property and a microscopic internal structural property. This paper presents a study of the bilinear constitutive model of negative Poisson’s ratio elastoplastic metamaterials, which analyzes the micro-rotation of cells and derives the constitutive model of these materials. Macroscopic experiments confirm that the deformation and failure mechanism of metamaterials align with the theoretical model, where the microscopic rotation characterizes the macroscopic deformation. Simulation analysis is carried out based on the elastic-plastic phase field method. The designability and potential for light weighting of negative Poisson’s ratio metamaterials provide a way to meet even more demanding requirements in the future, without sacrificing material performance.