A new periodic seismic metamaterial with ultra-low bandgap for lamb waves

In this paper, we propose a new seismic metamaterial (SM) that can cover the main frequency range of earthquakes by introducing curved boundaries on a square cross-section and reducing the contact area between adjacent cells, which results in a wide bandgap at very low frequencies. The vibration modes at the edge of the first bandgap are analyzed, and the effects of the geometric and material parameters of the rubber on the first bandgap are studied. Meanwhile, vibration experiments are performed. Finally, finite structural dynamics response analysis is performed. The results show that the structure has excellent damping performance in low frequency band. At the same time, it can achieve effective attenuation for Oroville, Gilroy, and Corralitos earthquakes, which has potential applications in the field of seismic isolation and attenuation of buildings.