A quasi-zero-stiffness elastic metamaterial for energy absorption and shock attenuation

A multi-step quasi-zero-stiffness metamaterial (MS-QZSM) is proposed, which exhibits potential applications in various engineering scenarios, such as multi-vibration mitigation and mechanical protection. At the level of the cell, the MS-QZSM is characterized by the elastic ring connected in parallel with two cross-curved beams respectively, which exhibits multiple deformation behaviors and quasi-zero-stiffness phases (force plateaus) under global compression load. Whithin the line elastic range of material, the proposed metamaterial can achieve QZS region. The multi-step QZS features of the MS-QZSM are theoretically analyzed, and validated by experiments and numerical calculations. Furtherly, the MS-QZSM performances of multiple deformation behavior and energy absorption are investigated by loading–unloading compressive experiments and simulations. Experiment results are in agreement with the simulation results, which show that there are two force plateaus and an obvious hysteretic loop. MS-QZSM has no structural damage during deformation, but plastic deformation occurs. In the area of multi-vibration mitigation and mechanical protection, the findings of this study can expand application prospects of metamaterial in engineering structures.