A Novel Acceleration Method for Crack Computation Using Finite Element Analysis in Eddy Current Testing

Finite element analysis plays an essential role in the field of eddy current computation and analysis for nondestructive testing applications. There are some analytical solutions that can be used to solve eddy current problems, however, in most cases, there is no suitable analytical method, i.e., the test sample with arbitrary geometry or with arbitrary shape of crack. Therefore, finite element method (FEM) is a fundamental tool in conducting the investigations. A key feature of using FEM for eddy current simulation is being versatile but slow. In this article, exploiting the fact that the crack only causes a small perturbance in fields in the surrounding region, a novel crack calculation acceleration method is proposed. The algorithm proves that the calculation can be mainly executed within the perturbance domain. Both numerical and experimental tests have been conducted for verification. The speed of the calculation is enhanced greatly (up to 34 folds in the tested cases) while deviation from the full solution is within 5%. Moreover, the measured results have a good agreement with the simulated ones under different depths of crack.