EXPERIMENTAL INVESTIGATION AND FINITE ELEMENT METHOD SIMULATION OF TIME DOMAIN PULSED EDDY CURRENT TECHNIQUE ON NON-FERROMAGNETIC CONDUCTIVITY PLATES.

Pulsed eddy current (PEC) is an advanced non-destructive testing (NDT) technique based on the electromagnetic principle. The excitation consists of a broad frequency spectrum for detection of defects in various depths of specimens. This paper details out the experimental and simulation investigations in determining the correlation between PEC signals and conductivity of different nonferromagnetic materials. The finite element method (FEM) simulation work provided understanding on the underlying phenomena by visualising the eddy current density and magnetic field distribution in specimens with varying conductivity values. The FEM results show that conductivity affects the induced current density within the specimens. Specimens with high conductivities generate high current density within the specimen, which increases the net magnetic field acquired from the specimen. In addition, the results obtained from the conductivity experiments demonstrated good agreement with that of the FEM simulation. Both approaches generate increment in the amplitude of the net magnetic field acquired from specimens with different conductivity values. [ABSTRACT FROM AUTHOR]