关键词: 周期结构, 带隙特性, Rayleigh波, 局域共振, 隔震

Abstract: To mitigate the damage caused by seismic Rayleigh waves to structures, periodic surface wave metabarriers with double resonant cavities are proposed. The vibration isolation performance of the scale model is experimentally studied and verified using finite element simulation result. Consequently, the band structure and vibration transmission characteristics are further examined by using finite element method. The mechanism of bandgap formation is clarified in terms of eigenmodes and displacement field distributions. Simple analytical formulas for the dispersion curves of interactions between Rayleigh waves and vertical and horizontal resonant modes are derived. The results show that in the bandgap frequency range, Rayleigh wave attenuation is effectively validated through dynamic response analysis of surface wave metabarriers under actual ground motion using time history analysis. The peak ground acceleration in the horizontal direction can be reduced by 56.8% because part of the Rayleigh waves is localized to the resonant elements of the periodic surface wave metabarriers, while the rest is converted into bulk waves that propagate away from the ground surface. The study provides a new design idea for the ultra-low frequency vibration reduction and isolation application of periodic surface wave metabarriers.

Key words: periodic structure, band gap characteristic, Rayleigh waves, local resonance, seismic isolation