Design and mechanical behavior of 3D printed high tensile negative Poisson's ratio metamaterials

This paper focuses on the origami metamaterials with both negative Poisson's ratio effect and high tensile performance. The research is conducted by combining experiments and numerical simulations. Parametric models are established using HyperMesh, and finite element simulations are carried out with Ls-Dyna. Nylon PA2200 specimens are fabricated by Selective Laser Sintering (SLS), and quasi-static tensile tests are performed to systematically investigate their mechanical behavior and regulation mechanism. The research shows that the unit cell geometric parameters (level, gap width) have a significant regulatory effect on the material properties: the tensile performance of the three-level structure (N3) is 413% higher than that of the one-level structure (N1), and the maximum negative Poisson's ratio reaches −0.25; reducing the gap width can increase the negative Poisson's ratio effect by 38%. The material exhibits a unique “spoon-shaped” Poisson's ratio evolution law, and the negative Poisson's ratio effect of the high-level structures (N2, N3) can be maintained over a strain range of more than 100%. When the design is extended to three-dimensional tubular structures, it is found that they have novel deformation modes such as progressive strengthening and smooth failure. This study provides theoretical and experimental basis for the development of programmable negative Poisson's ratio high-tensile metamaterials, which have important application potential in fields such as flexible electronics and aerospace.