Interface Finite Element Method with Lower Calculation Amount for Step Size-varying Electro-quasistatic Field Problem

A novel FEM called interface finite element method (I-FEM) is proposed for the step size-varying electro-quasistatic field (EQS) in this paper. First, the corresponding equation and interface conditions for I-FEM are given. Then, the numerical principle of I-FEM is conducted. In the proposed method, by the inverse matrix modification lemma, the calculation amount of I-FEM is decreased greatly. Furthermore, the corresponding example is given to verify the effectiveness and correctness of I-FEM. At last, the error analysis and universal promotion of the proposed I-FEM are given. Compared with the normal FEM, I-FEM can greatly decrease the calculation amount while the numerical accuracy of I-FEM is even better than the normal FEM in some case.