复电阻率法二维有限元数值模拟

伴随着复电阻率法的广泛应用，发展精确和快速的正演和反演算法成为复电阻率法研究的重点.本文采用基于三角单元剖分的有限单元法进行了复电阻率二维数值模拟研究.为了提高计算速度，对无穷远边界进行了近似处理.整个正演计算过程分为两步，首先采用有限单元法计算四个不同频率的视复电阻率数据，然后对前一步得到的视复电阻率数据采用递推算法计算视Cole-Cole参数.采用这种正演算法与一维正演的结果进行了对比，验证了本文方法的正确性.设计了两个二维极化模型，数值模拟结果表明视复电阻率和Cole-Cole视参数等值线断面图对于异常目标体都有比较明显的反映.

Two-dimensional modeling of complex resistivity using finite element method

With wide application of complex resistivity method,searching precise,rapid forward and inversion algorithms has become the focus of complex resistivity research.We have developed a finite element algorithm for computing the complex resistivity response of general two-dimensional models in the paper.Triangular element grid is used in the finite element method(FEM).The simplifying boundary condition on infinite boundary is employed to improve the speed of calculation.The modeling takes two steps.Firstly,we compute apparent complex resistivity values for four different frequencies by FEM.Then,apparent Cole-Cole parameters are derived from these apparent complex resistivity values using a recursive method.The algorithm has been tested by comparing with one-dimensional algorithm.Two typical two-dimensional polarization models are used by the forward approach.The apparent complex resistivity and the apparent Cole-Cole parameters maps show that there are distinct anomaly features in the section maps of apparent complex resitivity and apparent Cole-Cole parameters.