A novel compression-torsion coupling metamaterial with tunable Poisson's ratio

Abstract

In this study, a three-dimensional compression-torsion coupled negative Poisson structure was designed by combining the perforated plate with the inclined rod out of the plane. This structure can realize the selection of the positive and negative Poisson's ratio of the three-dimensional structure by changing the direction of the inclined rod. The absolute value of the Poisson's ratio of the two structures is close to the same but the positive and negative are opposite. Both structures maintain close to the same stress–strain curve. This structural characteristic can realize the selection of an ideal Poisson's ratio without changing the mechanical properties of the structure. Two 3D compression-torsion coupling structures were printed using metal 3D printing technology, and compression tests were carried out in the axial and transverse directions. Then, parametric analysis was carried out under axial compression, including energy absorption and specific energy absorption analyses. The results show that the experimental and finite element results are in good agreement and the finite element simulation is accurate. The Poisson's ratio of this negative Poisson's ratio metamaterial is selectable under both axial and lateral pressure conditions, so the structure has the excellent characteristics of selectable Poisson's ratio in three mutually perpendicular axes. The results show that the absolute value of Poisson's ratio exceeds 1 when the structure is under lateral compression, which indicates that the lateral deformation rate of the structure is greater than the axial deformation rate under this compression form. Finally, two tubular structures with different arrangements were designed by using these two structural cells, and the ball passing test was carried out. The results show that different arrangements will cause the balls to experience different resistances when passing through different positions in the tube. Research shows that the structure has potential applications in energy absorption, biomechanical devices, smart actuators, and devices with special requirements for Poisson's ratio.