弹性波波场P波和S波分解的数值模拟

通常采用完全弹性波波动方程进行弹性波波场数值模拟，只能得到P波和S波的混合波场。若要进一步获得P波和S波的波场，一般是在得到混合波场之后再进行波场分离，或用声波方程单独模拟P波和S波波场，但是这些方法往往很难确保P波和S波的振幅不出现畸变。本文给出了完全弹性波波动方程的一种等价方程，该方程既含混合波场变量，也含纯P波和纯S波波场变量。用伪谱法求解该波动方程，在得到混合波场的同时，也得到了完全分离的纯P波或纯S波波场，并保留了P波和S波能量相互转换的信息。模拟波场分析表明，采用这种弹性波波场分解的数值模拟方法对认识弹性波的传播规律有重要意义。

Numerical modeling of P-wave and S-wave separation in elastic wavefield.

Commonused the full elastic wave equation to carry o ut the numerical modeling of elastic wavefield only obtained a hybrid wavefield of P-wave and S-wave.When you want to obtain P-wave and S-wave wavefield,ge nerally the wavefield separation is carried out after hybrid wavefield being obt ained or using acoustic equation to model the P-wave and S-wave wavefield,but these methods are very difficult to ensure the amplitude of P-wave and S-wave do not disorder.The paper gave an equivalent equation of full elastic wave equat ion,which contains variations of both the hybrid wavefield and the pure P-wave and S-wave wevefield. Using pseudo-spectrum method to solve the wave equation, obtained totally separated wavefield of pure P-wave and S-wave while obtaining hybrid wavefield,and preserved the information of mutual transformation of P-w ave and S-wave energy.The analysis of modeling wavefield showed using numerical modeling of elastic wave separation has important meaning in respect of knowing the propagating rule of elastic wave.