Modeling and simulation for defect depth estimation using pulsed eddy current technique

Abstract

A finite element simulation for defect depth estimation using the pulsed eddy current (PEC) technique is presented in this paper. In this work, we investigate PEC inspection on defect with different depths, through the transient magnetic flux density profile from eddy current and defect interaction in a stainless steel sample. The investigation is implemented via time-stepping finite element method (FEM) modelled in 3D using COMSOL. The estimation of defect depth was made possible by the peak amplitude feature of the differential magnetic flux density profile acquired by the PEC coil. The underlying phenomena of the acquired results is then observed and discussed through the visualisation of the resultant eddy current density for different defect depths obtained from the simulation. The simulation results indicate the potential of detection and quantitative evaluation of defect using the PEC technique. It is expected the investigation will help in the future work of PEC in terms of sensor development and inversion models for defect characterisation.