Finite Element Modeling of Pulsed Eddy Current Applied to Ferrous and Titanium Fasteners in F/A-18 Airplane Wing Structure

V. K. Babbar[1], P. R. Underhill[1], T. W. Krause[1]
[1]Department of Physics, Royal Military College of Canada, Kingston, ON, Canada
Published in 2013

Pulsed eddy current (PEC) is being developed to detect stress corrosion cracks between fasteners on the inner wing spars of the F/A-18 Hornet aircraft. The spars are located below a thick carbon/epoxy wing skin, and so cannot be detected by conventional eddy current techniques without disassembling the wing structure. Also, the effectiveness of PEC to detect defects at greater depths is strongly influenced by the electromagnetic properties of the fastener materials. The present work uses finite element modeling to investigate the effect of the two possible fastener materials, ferrous and titanium (Ti), on the PEC signals. It also investigates the effect of a slight off-centered probe for each of the fastener types. The results are in qualitative agreement with the experiment.