Abstract
Detecting hidden damage at the second layer of lap joint structures in aircraft by using eddy current techniques is difficult because the cracks are usually located beneath the head of the rivets, which cause large signals that mask the relatively smaller signals from the second layer cracks. In addition, using lower frequency excitation for deeper penetration of the eddy currents reduces the signal-to-noise ratio. Several new techniques have been tried, such as using a sheet inducer to increase the penetration depth or using sensors that have a frequency independent response, to improve the signal to noise ratio [1, 2]. To better extract the information due to the cracks beneath the rivet at the second layer, we have developed a phase analysis of the magnetic field produced from the eddy currents induced by the sheet inducer.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
G. L. Fitzpatrick, D. K. Thome, R. L. Skaugset, and E. Y. C. Shih, in Review of Progress in QNDE, vol. 12, D. O. Thompson and D. E. Chimenti, Eds., New York: Plenum Press, pp. 617–624, 1993.
Y. P. Ma and J. P. Wikswo, Jr., in Review of Progress in QNDE, Vol. 13, D. O. Thompson and D. E. Chimenti, Eds., New York: Plenum Press, pp. 303–309, 1994.
Yu Pei Ma and John P. Wikswo, Jr., in J. of Nondestructive Evaluation, Vol.14, No.3, 1995. in press
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1996 Plenum Press, New York
About this chapter
Cite this chapter
Ma, Y.P., Wikswo, J.P. (1996). Depth-Selective Squid Eddy Current Techniques for Second Layer Flaw Detection. In: Thompson, D.O., Chimenti, D.E. (eds) Review of Progress in Quantitative Nondestructive Evaluation. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-0383-1_51
Download citation
DOI: https://doi.org/10.1007/978-1-4613-0383-1_51
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-8027-6
Online ISBN: 978-1-4613-0383-1
eBook Packages: Springer Book Archive