1 1Department of Electronics & Electrical Engineering, Centre for Ultrasonic Engineering (CUE), University of Strathclyde, 99 George Street, Glasgow, G1 1RD UK.
2 Département de génie mécanique, L'École de Technologie supérieure, 1100 Rue Notre-Dame O, Montreal, Québec H3C 1 K3 Canada.
3 2John Abbott College, 21275 Lakeshore Dr, Sainte-Anne-de-Bellevue, Québec H9X 3L9 Canada.
4 4Department of Mechanical & Industrial Engineering, Concordia University, 1455 De Maisonneuve Blvd. W., Montreal, Québec H3G 1M8 Canada.

Finite Element Modelling of a Reflection Differential Split-D Eddy Current Probe Scanning Surface Notches.

J Nondestr Eval. 2020;39(2):29

Authors: Mohseni E, França DR, Viens M, Xie WF, Xu B

Abstract

Differential eddy current probes are commonly used to detect shallow surface cracks in conductive materials. In recent years, a growing number of research works on their numerical modelling was conducted since the development of analytical or semi-analytical models for such a sensor may be prone to intractable complications. In this paper finite element modelling (FEM) has been employed to simulate the interaction of a reflection differential split-D probe with surface electrical discharge machined (EDM) notches in 3-dimensional (3-D) half-space. In order to attain a better insight into the correct setup of the FEM parameters, a simple multi-turn cylindrical absolute coil has also been modelled. The outcome generated through the simulated scan of this absolute coil over a surface notch in aluminum is validated with existing experimental impedance data taken from the literature. Parameters contributing to reliable FEM simulation results, such as maximum mesh size, mesh distribution, the extent of the surrounding air domain and conductivity of the air are investigated for the 3-D modelling of both absolute and differential probes. This study shows that the simulation results on a commercial reflection differential split-D surface pencil probe closely estimate the experimental measurements of the probe's impedance variations as it scans three EDM notches having different depths in aluminum. The simulation results, generated by Comsol Multiphysics FEM package (COMSOL I, COMSOL multiphysics reference manual, version 5.3, COMSOL AB, 2018, www.comsol.com), for the cases of absolute and differential probes are checked for their extent of validity.

PMID: 32214578 [PubMed]