瑞利面波数值模拟中的PML吸收边界条件  

PML ABSORBING BOUNDARY CONDITION FOR NUMERICAL MODELING OF RAYLEIGH WAVE

作　　者：熊章强[1] 唐圣松[1] 张大洲[2] 

机构地区：[1]中南大学信息物理工程学院,湖南长沙410083 [2]中国地质大学地球物理与空间信息学院,湖北武汉430074

出　　处：《物探与化探》2009年第4期453-457,共5页Geophysical and Geochemical Exploration

基　　金：江西省自然科学基金项目(05560003);江西省科技攻关项目联合资助

摘　　要：建立了弹性介质情况下完全匹配层(PML)吸收边界的2×12阶速度—应力交错网格有限差分算法,讨论了PML吸收边界条件的构建及其有限差分算法实现。通过与未加吸收边界及加常规指数衰减吸收边界3种情况下比较的波场模拟计算表明,PML吸收边界具有吸收更干净且能够吸收各种角度的边界反射等优点,其吸收率(吸收能量与未吸收能量之比)达到99.99%,很好地消除了周期折叠效应,使得所要计算的波场特征变得非常清晰,瑞利面波清楚地显示在波形记录上。The algorithm of the finite difference of-order velocity-stress staggered grids has been built, which is suitable for the perfectly matched layer （PML） absorbing boundary for elastic media. Meanwhile, the construction of the PML absorbing boundary condition and the realization of the finite-difference algorithm are discussed in detail. Wave field modeling calculations show that, compared with the conventional decaying exponential absorbing boundary and non-absorbing boundary, the PML absorbing boundary can perform absorption much more clearly and absorb the boundary reflection from various angles, whose absorptivity （ the ratio of absorption energy to unabsorbable energy） can reach 99.99%. The PML absorbing boundary can well eliminate the periodic folding effects, which makes the calculation of the wave field characteristics very distinct, and the Rayleigh wave can be dearly shown in the waveform record.

关 键 词：瑞利面波 数值模拟 完全匹配层吸收边界 有限差分 

分 类 号：P631.4[天文地球—地质矿产勘探]