Use of last developments in Comsol to solve Eddy Current Non Destructive Testing Problems
As part of its research, the Group of Electrical Engineering-Paris (GeePs) uses COMSOL Multiphysics software for applications such as material modelling in Electrical Engineering, electromagnetic compatibility and Eddy current non-destructive testing (EC-NDT). EC-NDT is an easy-to-use and low-cost technique with a wide range of applications, including defect detection, thickness or electrical conductivity measurement and mechanical stress analysis. This paper is the continuation of a previous paper published in 2010 [1] carried out under version 3.5 of Comsol Multiphysics. Since then, several other papers have been published in connection with the use of Comsol Multiphysics in EC-NDT, such as [2][3]. The aim of this contribution is to highlight the new advances in the software in its version 6.2, which allow more accurate and faster resolution of this kind of low-frequency electromagnetic problem. To solve this kind of problem AC/DC module is used in 3D. The EC-NDT problems often involve areas of small thickness (skin depth, fine cracks, small spacing between probe and specimen to be tested, stacking of thin layers). Generating a mesh in these areas can be tricky. The quality of the mesh will determine the reliability of the solution and the computation time. Several solutions will be proposed to deal with this zone such as the use of boundary layers, specific boundary conditions, prismatic extruded mesh... Each case with its proposed solution will be evaluated on benchmark cases or compared to an analytical solution and discussed in the final paper. New solutions to reduce computation time such as distributed computed will be presented.
