2.5D DC resistivity forward modeling based on a local weak form element-free method
MA Changying1,2,3, YAN Lingling1,3, YAO Zhen'an1,3, LIU Jianxin2, ZHAO Wenxue1,3, ZHOU Cong1,3
1. Engineering Research Center for Seismic Disaster Prevention and Engineering Geological Disaster Detection of Jiangxi Province, East China University of Technology, Nanchang, Jiangxi 330013, China; 2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University), Ministry of Education, Changsha, Hunan 410083, China; 3. School of Geophysics and Measurement-Control Technology, East China University of Technology, Nanchang, Jiangxi 330013, China
Abstract：The traditional numerical simulation method relies on elements based on nodal connection information, so its application is limited. Although the element-free Galerkin method(EFGM) based on the global weak form does not require the division of elements based on nodal connection information, it still relies on the background quadrature elements divided in the global domain. In this paper, the partition of unity quadrature method is used to transform the global local integration into nodal local domain integration based on EFGM. Therefore, the background quadrature element divided in the global domain is not needed, and the dependence on the element is further reduced. As a result, 2.5-dimensional direct current(DC) resistivity forward modeling based on a local weak form elementfree method is realized with higher flexibility and accuracy. The proposed method, the EFGM, and the finite element method(FEM) are respectively used to simulate different geoelectric models, and the results are compared, which prove the correctness and effectiveness of the proposed method for the forward modeling of DC resistivity. In addition, the flexibility and adaptability of the proposed method are better than those of EFGM and FEM, with higher accuracy and low computational efficiency. In order to improve the accuracy of this method in simulating the undulating terrain, node encryption is carried out in the undulating terrain, and Gaussian points outside the terrain are not calculated. The results are basically consistent with those obtained by the EFGM and FEM.
麻昌英, 闫玲玲, 姚振岸, 柳建新, 赵文学, 周聪. 基于无单元局部弱式法的2.5维直流电阻率正演[J]. 石油地球物理勘探, 2023, 58(4): 1002-1016.
MA Changying, YAN Lingling, YAO Zhen'an, LIU Jianxin, ZHAO Wenxue, ZHOU Cong. 2.5D DC resistivity forward modeling based on a local weak form element-free method. Oil Geophysical Prospecting, 2023, 58(4): 1002-1016.
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