六方和斜方各向性介质一维横波双折射正演数值模拟

FORWARD NUMERICAL MODELLING OF ONE-DIMENSION SHEAR-WAVE BIREFRINGENCE FOR HEXAGONAL AND RHOMBIC ANISOTROPIC MEDIUM

长春地质学院

Changchun College of Geosciences

本文从本构方程出发,推导了一维横波双折射有限元素法正演模拟公式.这是一种一维介质各向异性的模拟,与水平层状介质垂直入射平面横波的传播相对应。不同的层状介质,其速度各向异性和本征方位的方向是不同的,可以模拟各向同性与各向异性交混的层状介质。本文用这种模拟方法计算了横波双折射的数值解,并对所得结果进行了分析讨论。该方法是一维情况下研究横波双折射的有力工具,可以期望成为一维横波双折射反演的有力工具。

Based on the constitutive equation,the formula for one-dimension shear-wave birefraction forword modelling by finite element method was deduced. Such a modelling for one-dimension anisotropic medium is corresponding to the propagation of the plane wave in the horizontally layered medium with a vertical incidence. In each layer of the medium,both of the velocity anisotropy and the direction of the eigenazimuth could be variant. The above mentioned modelling could, also, be suitable for those which are composed of both the isotropic and the anisotropic medium. By using the technique recommended, the numerical solution of the shear-wave refraction was calculated and the correspondent discussion was also made. Such a technique is a powerful fool for shear-wave birefraction study under the condition of one-dimension. Also, it is expected to become more effective for the one -dimension shear-wave birefraction inversion.