Finite Element Analysis of Axisymmetric Geometries in Quantitative NDE

Solution of the inversion problem in quantitative eddy current NDE requires an adequate mathematical model to describe the complicated interactions of currents, fields and flaws in materials. Existing analytical techniques are not capable of accommodating materials with nonlinear magnetic characteristics or awkward flaw shapes. This paper describes a finite element computation of the complex impedance of an eddy current sensor in axisymmetric testing configurations, some with defects and gives the corresponding magnetic flux distri-butions. The authors suggest that, because finite element analysis techniques are not limited by material nonlinearities and complex defect geometries, they can be applied to the development of computer based defect characterization schemes for realistic eddy current NDE applications