Finite element model of natural crack in eddy current testing problem

Eddy current testing (ECT) is one of nondestructive inspection techniques t o detect crack and eddy current analysis is important for the ECT. However, it is difficult to model a natural crack in finite element method (FEM), b ecause of the narrow gap and the complex shape. In this paper, a finite ele ment model for the natural crack is proposed. The conductivity for the fini te element model is expressed by a tensor. In the proposed finite element, the change in crack shape and contact condition are simulated by changing t he coefficients of the conductivity tensor. The proposed model Is applied t o a conductor plate model with a crack and a coil. The computation results are compared with the computation results of an artificial crack model. The validity of the proposed method is shown by the computation results.