Soil-expended seismic metamaterial with ultralow and wide bandgap

Abstract

The low-frequency wide-bandgap characteristics of the seismic metamaterial can suppress the propagation of vibrations and reduce the risk of extreme loadings such as earthquakes. The stringent requirement of lattice size extensively increawiths the cost of forming seismic metamaterial with general engineering materials. We design soil-expanded seismic metamaterial to reduce the scale restriction on artificial materials. Two types of soil-expanded lattice are created, and the bandgap characteristics for the lattice are obtained through the transfer matrix method. The propagation process for finite periodic lattice is simulated by the finite difference method in the time domain. It is found that the acceleration amplitudes in the wave propagation region are suppressed by 90% for the seismic metamaterial with rubber components. The response spectra further indicate that seismic metamaterials can reduce seismic risk in targeted areas.