Inversion of Eddy Current Data to Reconstruct Flaws by An Optimisation Process

Eddy current nondestructive testing has the potential for measuring the size and shape of defects in metals. In this study, measurements of probe impedance changes due to induced current interactions with simulated cracks have been used to reconstruct crack shapes through an optimisation technique. Impedance predictions are compared with the measurements and an estimate of the crack shape varied until the predictions and observations are in tolerable agreement. The computed crack estimate then approximates the real crack. Results are presented comparing reconstructed defect shapes with measured profiles.