A practical scheme for 3D geoelectrical forward modeling with finite-infinite element coupling method

Abstract

In this study, fast and visualized pre and post processing for infinite element method was achieved by customized development based on the universal 3D modeling software named GiD, while infinite elements were introduced to form the finite-infinite element coupling method, which could substitute the conventional mixed boundary conditions and solve the problems cased by artificial boundary conditions. For the customized development on GiD, we only need to program the so-called problem types with simple script language, then models could be build in the graphic interface and output in the format fitting our calculation program. As to our finite-infinite element method, Astley mapped wave envelope infinite elements were employed to continue the electrical potential to infinity. Then, a new type of shape functions was created and it was proved to be the optimal one in both accuracy and time consumption by comparing with several other shape functions. Finally, the availability and superiority of this coupling algorithm were confirmed by several numerical tests with various electrode arrays.