On the use of the 3D H-φ-formulation for the forward solution for eddy current nondestructive testing

Eddy current nondestructive testing has the potential for estimating the shape and size of defects in conducting materials. In the testing process an artificial defect is varied in size and position until the measured and estimated fields are in tolerable agreement. An accurate and fast three-dimensional field computation is therefore required which can resolve very small field perturbations generated by e.g. a subsurface crack. In this paper an implementation of a boundary element formulation with four variables on linear or quadratic isoparametric elements is presented, which is able to fulfil these requirements. The accuracy of the proposed method is validated with the TEAM benchmark problem No.6. Tests were also carried out for the TEAM Benchmark Problem No.15.