Perfectly matched layer-absorbing boundary condition for finite-element time-domain modeling of elastic wave equations  

时域有限元弹性波模拟中的位移格式完全匹配层吸收边界(英文)

作　　者：赵建国[1,2,3] 史瑞其[4] 

机构地区：[1]中国石油大学(北京)地球物理与信息工程学院 [2]油气资源与探测国家重点实验室 [3]CNPC物探重点实验室,北京102249 [4]中国海洋石油研究总院,北京100027

出　　处：《Applied Geophysics》2013年第3期323-336,359,共15页应用地球物理（英文版）

基　　金：sponsored by the National Natural Science Foundation of China Research(Grant No.41274138);the Science Foundation of China University of Petroleum(Beijing)(No.KYJJ2012-05-02)

摘　　要：The perfectly matched layer （PML） is a highly efficient absorbing boundary condition used for the numerical modeling of seismic wave equation. The article focuses on the application of this technique to finite-element time-domain numerical modeling of elastic wave equation. However, the finite-element time-domain scheme is based on the second- order wave equation in displacement formulation. Thus, the first-order PML in velocity-stress formulation cannot be directly applied to this scheme. In this article, we derive the finite- element matrix equations of second-order PML in displacement formulation, and accomplish the implementation of PML in finite-element time-domain modeling of elastic wave equation. The PML has an approximate zero reflection coefficients for bulk and surface waves in the finite-element modeling of P-SV and SH wave propagation in the 2D homogeneous elastic media. The numerical experiments using a two-layer model with irregular topography validate the efficiency of PML in the modeling of seismic wave propagation in geological models with complex structures and heterogeneous media.完全匹配层是地震波方程数值模拟中一种高效的吸收边界条件,本文目的在于将这种技术用于时域有限元弹性波数值模拟中。但时域有限元法是基于二阶位移格式的波动方程的数值模拟方法,所以一阶速度-应力格式的完全匹配层不能直接用于该数值模拟方法中。本文推导了二阶位移格式完全匹配层的有限元矩阵方程,实现了完全匹配层在时域有限元弹性波模拟中的应用。在二维均匀弹性介质P-SV波和SH波传播的有限元模拟中,完全匹配层对体波和面波具有近似零反射系数;不规则地表双层介质模型的数值实验验证了完全匹配层在复杂构造非均质地质模型中地震波传播模拟的效果。

关 键 词：Absorbing boundary condition elastic wave equation perfectly matched layer finite-element modeling 

分 类 号：P631.4[天文地球—地质矿产勘探]