共振型地震表面波屏障设计与性能分析

Design and Performance Analysis of Resonant Seismic Surface Wave Barriers

周期结构的带隙特性使得位于带隙频率范围内的振动或波动无法在结构中传播。基于该思想,设计了一种埋入式的地震表面波屏障以调控Rayleigh表面波的传播,并研究了该表面波屏障的主要设计参数及共振单元与支撑基础之间的连接约束关系等对弹性波频散曲线和表面波带隙形成的影响。结果表明:该埋入式的地震表面波屏障能够形成低频的表面波带隙,实现有效的衰减域;共振单元与支撑基础之间的约束关系会显著改变地震表面波屏障的频散曲线,不同的约束条件会影响表面波带隙的形成,甚至造成带隙的消失,在屏障设计与实现过程中应对影响两者发生相对运动的因素如摩擦力等进行考虑,进行合理设计。

A periodic structure has band-gap characteristics so that the vibrations or waves in the bandgap frequency range cannot propagate in the structure.Based on this concept,an embedded seismic barrier for manipulating Rayleigh surface waves is designed.The influence of the design parameters of the seismic barrier and the constraint conditions between the resonant element and the supporting foundation on the elastic wave dispersion curve and the formation of the bandgaps of seismic surface wave is studied.The results indicate that the embedded seismic metamaterial barrier can form a surface wave band gap in the low frequency region and realize an effective attenuation domain.The constraint conditions between the resonant element and the supporting foundation can significantly alter the band structure of the dispersion curve.Different constraint conditions can affect the formation of the surface wave bandgaps,and even cause the disappearance of the surface wave bandgaps.Thus,in the process of barrier design and implementation,factors,such as friction,that affect the relative movement between the resonant element and the supporting foundation should be considered and rationally designed.