Study on Energy Absorption Performances of Conical Negative Stiffness Metamaterials

Since negative stiffness metamaterials are reusable as energy-absorbing materials, it is necessary to investigate the energy-absorbing performances and reusability of negative stiffness metamaterials. The designed negative stiffness metamaterial was prepared with the 3D printing technology, and the energy absorption performance of the metamaterial in the multi-stable mode and the mono-stable mode was investigated by repeated loading experiments. The effect of the residual stress on the energy absorption performance of the metamaterial was studied with the natural aging method. The results show that, the specific energy absorption of the designed metamaterial first decreases and then stabilizes with the increase of the number of loading times in the case of repeated loading. In both the multi-stable mode and the mono-stable mode, the natural aging method can effectively release the residual stresses in the metamaterial, thus improving its repeated energy absorption performance.