Article Article
Enhanced Coating Disbond Detection Capabilities in Pipe Using Circumferential Shear Horizontal Guided Waves

Circumferential shear horizontal guided waves propagate in the circumferential direction of a pipe or pipelike structure and have particle displacements in the axial direction only. In this work, the circumferential shear horizontal wave phase and group velocity dispersion curves and wave structures are calculated for a layered elastic/viscoelastic annular structure using a semianalytical finite element technique. The results are used to select modes and frequencies that are appropriate for the reliable detection of disbonded protective coatings. Time, amplitude and frequency based disbond detection features are identified and utilized in the design of a disbond detection algorithm. Circumferential shear horizontal waves are generated in a coal tar enamel coated pipe specimen using a pair of electromagnetic acoustic transducers (EMATs) arranged in a manner conducive to data normalization. Data are collected in several regions with coating disbonds of varying size. It is found that the technique is able to reliably detect coating disbonds and sort them according to size. Results from a field test are also presented in which data were collected from a moving sensor carriage. Though experimentally validated for a single coating type and thickness, the developed disbond detection philosophy is readily applied to other coating types and thicknesses.

Aaron, J., J. Gore, R. Dalton, S. Eaton, A. Bowles, O. Thomas and T. Jarman, “Development of an EMAT In-Line Inspection System for Detection, Discrimination, and Grading of Stress Corrosion Cracking in Pipelines,” DOE Award No. DE-FC26-01NT41154 Annual Technical Progress Report, Houston, Tuboscope Pipeline Services, 2003, p. 49. Al-Qahtani, H., T. Beuker and J. Damaschke, “In-Line Inspection with High-Resolution EMAT Technology Crack Detection and Coating Disbondment,” Proceedings of 20th International Conference on Pipeline Pigging, Integrity Assessment and Repair, Houston, 2008. Barshinger, J.N. and J.L. Rose, “Guided Wave Propagation in an Elastic Hollow Cylinder Coated with a Viscoelastic Material,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 51, 2004, pp. 1547–1556. Bartoli, I., A. Marzani, F. Lanza di Scalea and E. Viola, “Modeling Wave Propagation in Dampled Waveguides of Arbitrary Cross-Section,” Journal of Sound and Vibration, Vol. 295, 2006, pp. 685–707. Bernard, A., M.J.S. Lowe and M. Deschamps, “Guided Wave Energy Velocity in Absorbing and Non-Absorbing Plates,” The Journal of the Acoustical Society of America, Vol. 110, 2001, pp. 186–196. Christensen, R.M., Theory of Viscoelasticity: An Introduction, New York, Academic Press, 1981. Gridin, D., R.V. Craster, J. Fong, M.J.S. Lowe and M. Beard, “The High- Frequency Asymptotic Analysis of Guided Waves in a Circular Elastic Annulus,” Wave Motion, Vol. 38, 2003, pp. 67–90. Hayashi, T., W.-J. Song and J.L. Rose, “Guided Wave Dispersion Curves for a Bar with an Arbitrary Cross-Section, a Rod and Rail Example,” Ultrasonics, Vol. 41, 2003, pp. 175–183. Hirao, M. and H. Ogi, “An SH-Wave EMAT Technique for Gas Pipeline Inspection,” NDT&E International, Vol. 32, 1999, pp. 127–132. Liu, G. and J. Qu, “Transient Wave Propagation in a Circular Annulus Subjected to Transient Excitation on its Outer Surface,” The Journal of the Acoustical Society of America, Vol. 104, No. 3, 1998, pp. 1210–1220. Luo, W., J.L. Rose and H. Kwun, “Circumferential Shear Horizontal Wave Axial-Crack Sizing in Pipes,” Research in Nondestructive Evaluation, Vol. 15, 2004, pp. 149–171. Luo, W., X. Zhao and J.L. Rose, “A Guided Wave Plate Experiment for a Pipe,” Journal of Pressure Vessel Technology, Vol. 127, 2005, pp. 345–350. Meirovitch, L., Analytical Methods in Vibrations, Toronto, Collier-Macmillian Canada, 1967. Mu, J. and J.L. Rose, “Guided Wave Propagation and Mode Differentiation in Hollow Cylinders with Viscoelastic Coatings,” The Journal of the Acoustical Society of America, Vol. 124, No. 2, 2008, pp. 866–874. Nestleroth, J.B. and G.A. Alers, “Enhanced Implementation of MFL Using EMAT Sensors to Detect External Coating Disbondment,” PRCI Contract PR-3-9715 Final Report, Houston, Technical Toolboxes, 2002, p. 71. Qu, J., Y.H. Berthelot and Z. Li, “Dispersion of Guided Circumferential Waves in a Circular Annulus,” Review of Progress in Quantitative Nondestructive Evaluation, Vol. 15A, D.E. Chimenti and D.O. Thompson, eds., New York, AIP, 1996, pp. 169–176. Thompson, R.B., G.A. Alers and M.A. Tennison, “Application of Direct Electromagnetic Lamb Wave Generation to Gas Pipeline Inspection,” Proceedings of the IEEE Ultrasonics Symposium, Boston, 1972. Valle, C., J. Qu and L.J. Jacobs, “Guided Circumferential Waves in Layered Cylinders,” International Journal of Engineering Sciences, Vol. 37, 1999, pp. 1369–1387. Valle, C., M. Niethammer, J. Qu and L.J. Jacobs, “Crack Characterization Using Guided Circumferential Waves,” The Journal of the Acoustical Society of America, Vol. 110, No. 3, 2001, pp. 1282–1290. Van Velsor, J.K., “Circumferential Guided Waves in Elastic and Viscoelastic Multilayered Annuli,” doctoral thesis, Engineering Science and Mechanics, The Pennsylvania State University, 2009. Viktorov, I.A., Rayleigh and Lamb Waves, Physical Theory and Applications, New York, Plenum Press, 1967. Zhao, X. and J.L. Rose, “Guided Circumferential Shear Horizontal Waves in an Isotropic Hollow Cylinder,” The Journal of the Acoustical Society of America, Vol. 115, No. 5, 2004, pp. 1912–1916.
Usage Shares
Total Views
148 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage