Crushing Behavior and Energy Absorption Performance of a Novel 3D Folded Structure with Negative Poisson's Ratio

A novel 3D folded structure (3D‐FS) with negative Poisson's ratio (NPR) is proposed herein. The deformation mechanism and energy absorption properties are investigated by the experiment and simulation. An analytical model describing the two‐plateau stress phases is presented based on the experimental data. Numerical simulations are performed to analyze the influence of the structural geometry parameters on the plateau stress, energy absorption properties and NPR, and to establish the relationship between specific energy absorption and wall thickness ratio for the two‐plateau stress phases. A comparison of NPR and energy absorption is performed with the warp and woof periodic auxetic cellular structure (WWPACS). The results show that 3D‐FS has an obvious NPR effect and bistable performance under compressive loading. With the star re‐entrant angle increasing, the first‐plateau stress increases while the second‐plateau stress decreases; meanwhile, the NPR effect and energy absorption capacity are enhanced. The NPR effect of 3D‐FS is more evident than that of WWPACS, and the maximum NPR is 1.14 times of WWPACS. The specific energy absorption (SEA) of 3D‐FS is 2.21 times larger than that of WWPACS when the compressive compression strain is 0.60.