基于快速多极间接边界元法的地震超材料隔震效应研究

本文将快速多极间接边界元法 (FMIBEM) 应用至地震超材料对地震波的散射模拟,并提出一种周期性隔震材料——岩土复合地震超材料 (RSCSM)。在精度验证基础上,对RSCSM的带隙结构及不同单晶胞结构下的隔震效果与带隙范围进行详细的数值分析。结果表明：采用FMIBEM能够有效地处理大型地震超材料对地震波的宽频散射问题；RSCSM能够隔离地震波超低频段隙,方形晶胞结构产生的带隙宽度(0.5-17 Hz与54-72 Hz)涵盖了地震波产生危害的主要频段(0.5-2 Hz),隔震效果可达35%以上；改变RSCSM的单晶胞结构会对地震超材料带隙结构产生重要影响。本文研究为二维地震超材料对地震波散射的模拟提供一种高效方法,研究结论可为地基隔震设计提供部分科学依据。

Research on seismic isolation effect of seismic metamaterials based on fast multipolar indirect boundary element method

In this paper, the fast multipole indirect boundary element method (FMIBEM) is applied to simulate the scattering of seismic waves by seismic metamaterials, and a periodic seismic isolation measure - rock soil composite seismic metamaterials (RSCSM) is proposed. On the basis of accuracy verification, this paper conducts a detailed numerical analysis of the isolation effect and band gap range of RSCSM under the band gap structure and different single cell structures. The results show that using FMIBEM can effectively deal with the broadband scattering of seismic waves by large seismic metamaterials; RSCSM can isolate the ultra-low frequency band gap of seismic wave. The band gap width (0.5-17 Hz and 54-72 Hz) generated by square cell structure covers the main frequency band (0.5-2 Hz) of seismic wave hazards, and the isolation effect can reach more than 35%; Changing the single crystal cell structure of RSCSM will have an important impact on the band gap structure of seismic metamaterials. This study provides an efficient method for simulating the scattering of seismic waves by two-dimensional seismic metamaterials, and the conclusions of numerical analysis can provide some scientific basis for the isolation design of the foundation serving the project.