Buckling induced negative stiffness mechanical metamaterial for bandgap tuning

Negative-stiffness mechanical metamaterials that can achieve bandgap tuning are a novel area of intense interest, enabling vibration control as well as a wide range of mechanical properties. In this paper, a negative-stiffness mechanical metamaterial consists of beam elements that can be reconfigured for large deformations and the bandgap can be tuned by its deformation behavior. The deformation process of the proposed negative-stiffness metamaterial under uniaxial compression, as well as the band structure and vibration characteristics of the metamaterial under different deformation states are analyzed by a combination of numerical simulation and experiment. The research results show that the proposed negative-stiffness metamaterial suffers from buckling instability and large deformation during uniaxial compression., and has different band structures and band gap ranges under different deformation states. Thus, bandgap tuning can be achieved by the deformation of negative stiffness metamaterials. Furthermore, negative stiffness metamaterials with different angles exhibit different results in bandgap tuning. Finally, the performance of vibration transfer is verified by experiments. This study may provide a new avenue for the related research and design of negative-stiffness mechanical metamaterials with bandgap tuning capabilities.