弹性波边界元法正演模拟

BOUNDARY ELEMENT METHOD FOR ELASTIC WAVE FORWARD MODELING

弹性波边界元地震模型方法（ＢＥＥＳＭ），实现了二维和三维问题的纵、横波及转换波的同时模拟，并且能模拟任意复杂构造的地震声波正演模型．根据地震模型的特点，本文发展了数值积分计算与矩阵消元同步进行的块状高斯消元法；用解析法处理奇异积分；用无限元法处理边界吸收问题；采用单元长度随介质速度和计算频率变化的变单元算法，及自动剖分单元等技术，提高了计算精度，节省了内存，缩短了计算时间．

Boundary element elastic wave seismic model method (BEESM) is applied to the numerical simulation of the acoustic and elastic wavefilds for 2-D and 3-Dcomplex models. Based on the characteristics of seismic model,this paper improves block Gaussian elimination method, in which both numerical integral calculation and matrix elimination are performed alternately,removing the singularities inherent to me boundary integral equation approach by using analytical method, tackling the absorbing boundary problem by use of infinite elements, adopting a variable element dimension technique that the element dimension is changed with medium velocity and calculated frequency. These techniques result in less internal storage,fast operation and high accuracy.