Superposition method taking account of relative position change in finite element analysis for eddy current problem

For the problem in which relative positions of two or more objects change, such as a motor, it is necessary to generate the finite element mesh for each position. In this case, a great deal of labor is required to generate the finite element mesh. Accordingly, it is important to avoid the regeneration of the finite element mesh in the eddy current problem with the relative position change. In this paper, a method of superposition for the finite element models is proposed to take account of the relative position change. In the proposed method, the whole finite element model including two or more objects is obtained from the superposition method of the computation results of simple finite element models including the object. The computation results of each simple finite element model are related by both the finite element method based on the reduced magnetic vector potential technique and integral equations with respect to the eddy current and the magnetization of the other finite element model. These formulations are shown. The computation result of the whole model is not obtained only by these equations. Because the interactions between the objects can not be expressed only by these equations. Accordingly, the iterative calculation procedure to take account of the interactions is shown. The proposed method is applied to an ECT (eddy current testing) model and it is shown that the regenerating of the finite element mesh for the relative position change becomes unnecessary.