Simulation Study On Application Of Eddy Current Testing To Measure The Thickness Of Tubular Metal Matrix Based On Finite Element

The coated metal pipes and tubular-type containers are commonly used in petroleum,chemical and Aerospace industries. The coating thickness will affect the performance of themetal materials. After the coating is complete and working hours, the coating thickness mustbe measured. So the thickness measurement of tubular metal matrix coating has practicalsignificance.According to Maxwell equation, the three dimensional eddy current field has beencreated. Then based on geometric characteristics and boundary conditions of eddy currenttesting,3D finite element models of coating thickness on tubular metal matrix byeddy-current testing is built by finite element analysis software ANSYS, respectively, themagnetic flux distribution of the electromagnetic field, the eddy current distribution inmeasured and the coil impedance value are computed by the harmonic electromagneticanalysis.This thesis focuses on studying the factors affecting the accuracy of the thicknessmeasurement of tubular metal matrix coating. Based on the change of coil impedance, thethickness and curvature radius of tubular metal matrix effects on eddy current signal and themeasure precision of coating thickness have been investigated, and normalizes the impedancedata of the probe coil. Obtaining the EC sensor calibrated on a plate validate the finite elementsimulation and analysis is feasible and effective. The curvature radius and thickness ranges oftubular metal matrix are obtained that fulfilled the accuracy.To investigate the effects of the probe geometric parameters on performance of probe.The conclusions from the study provide guidance for the design of probe coil. Based on thetheoretical analysis of thickness measurement by eddy current, the experimental system for coating thickness measurement is set up, and the lift-off distance of different tubular matrix ismeasured. The experiment results show that this probe can measure the coating thickness oftubular matrix which curvature radius is greater than60mm and thickness is greater than4mm.The measure precision of the eddy current probe for liftoff can reach0.1mm,when testing thecoating thickness which is5mm,This study provide the valuable reference for coatingthickness on tubular matrix by Eddy Current Testing in the practical application.