Ultrasonic Defect Mapping Using Signal Correlation for Nondestructive Evaluation (NDE)
Publication: Publication Date: 1 May 2015Testing Method:
This article presents the application of a signal correlation technique to automatically classify ultrasonic A-scan signals for defect and defect-free regions in isotropic and anisotropic materials. First, feature extraction was implemented by generating a reference A-scan signal of a defect-free area using an autocorrelation function and statistics. Then, a cross-correlation function, utilized as a feature detector, was applied to the reference signal and a signal of interest (SOI) to detect defect-free features in an SOI. The correlation result was considered as a pattern containing both defect and defect-free features. Next, the pattern was classified by measuring the similarity between features of the reference signal and an SOI based on their Euclidean distance. Each A-scan signal classification result was then plotted on a 2D map based on its position on the specimen. The present work uses multiple correlation functions and statistics to classify defect signals rather than relying on an inspector’s prior knowledge to interpret C-scan data, and has particular value in automated ultrasonic signal classification and characterization.
- D. K. Hsu and M. S. Hughes. Journal of the Acoustical Society of America 92(2):669–675 (1992).
- B. B. Djordjevic. Proceedings of Ultrasonic International, Butterworth Heinemann, Vienna, Austria (1993).
- J. S. Sandhu, H. H. Wang, and W. J. Popek. Proceedings of Conference on Nondestructive Evaluation of Materials and Composites, pp. 117–124 (1996). 106 S. LI ET AL.
- M. Lasser. Review of Progress in Quantitative Nondestructive Evaluation. Vols. 17a and 17b, pp. 1713–1719. Springer US, New York (1998).
- W. Hillger. Proceedings of 15th World Conference on Non-Destructive Testing, Rome, Italy (2000). Available at http://www.ndt.net.
- B. B. Djordjevic. Proceedings of 15th World Conference on Non-Destructive Testing, Rome, Italy (2000). Available at http://www.ndt.net.
- ASTM Standard E2580-12. Ultrasonic Testing of Flat Panel Composites and Sandwich Core Materials Used in Aerospace Applications. ASTM International, West Conshohocken, PA (2012).
- A. Poudel, J. S. Sandhu, T. P. Chu, and C. Pergantis. Proceedings of the 23rd Annual Research Symposium and Spring Conference, Memphis, TN (2014).
- B. B. Djordjevic. Proceedings of the 10th International Conference of the Slovenian Society for Non-Destructive Testing, Ljubljana, Slovenia (2009).
- R. Cepel, K. C. Ho, B. A. Rinker, D. D. Palmer, T. O. Lerch, and S. P. Neal. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 54(9):1841–1850 (2007).
- P. M. T. Broersen. Automatic Autocorrelation and Spectral Analysis. Springer, London (2006).
- R. O. Duda, P. E. Hart, and D. G. Stork. Pattern Classification. Wiley, New York (2001).
- A. Poudel, R. Kanneganti, L. Gupta, and T. P. Chu. Proceedings of ASNT 22nd Research Symposium and Spring Conference, Memphis, TN (2013).
- S. Li, X. Zhou, A. Poudel, and T. P. Chu. Proceedings of ASNT 2013 Fall Conference, Las Vegas, NV, November 4–7, 2013.
- J. Canny. IEEE Transactions on PAMI 8(6):679–698 (1986).
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