A sound beam focusing technique called synthetic focusing using linear array (SFLA) has been developed. The technique is based on acquiring the raw B-scan image using a divergent sound beam emanating from individual elements of an array and then carrying out synesthetic aperture focusing technique (SAFT) processing of the raw data to achieve sound beam focusing throughout the thickness of the sample. The sound beam focusing is achieved using much less advanced resources as compared to the focal law based phased array technique. The data size for post processing is also significantly smaller as compared to the one acquired using full matrix capture (FMC). The sensitivity for the detection of discontinuities and the ability to resolve them from each other using SFLA technique has been assessed on aluminum and carbon steel samples. The results obtained by SFLA technique have been found to be comparable to those obtained by the full matrix capture – total focusing method (FMC + TFM). The focusing ability of SFLA technique has been utilized for accurate depth sizing of a planar flaw in the weld joint.
ASME Boiler and Pressure Vessel Code: Section XI: Rules for in-service inspection of nuclear power plant components, New York, New York. American Society of Mechanical Engineers. 2015.
Azar, L., Y. Shi, and S.C. Wooh, “Beam Focusing Behaviour of Linear Phased Arrays,” NDT&E International, Vol. 33, No. 3, 2000, pp. 189–198.
Chahbaz, A. and R. Sicard, (Mar 2003). “Comparative Evaluation Between Ultrasonic Phased Array and Synthetic Aperture Focusing Techniques,” AIP Conference Proceedings, Vol. 657, No. 1, pp. 769–776.
Chapman, R. K., “The Assessment of Defect Measurement Errors in the Ultrasonic NDT of Welds,” CEGB Guidance Document,
OED/STN/87/20137/R, Issue 1, 1987.
Charlesworth, J. P., and J.A.G. Temple, Engineering Applications of Ultrasonic Time-of-Flight Diffraction, 2nd Edition, Ultrasonic Inspection in Engineering Series, Baldock: Research Studies Press Ltd., 2001,
Dias, J. Fleming, “Construction and Performance of an Experimental Phased Array Acoustic Imaging Transducer,” Ultrasonic Imaging, Vol. 3, No. 4, 1981, pp. 352–368.
Ezzaidi, M., D. Decultot,, D. Maze, and A. Moudden, “Measurement of Thickness of a Cylindrical Shell with a Focused Beam,” NDT&E International, Vol. 35, No. 7, 2002, pp. 433–436.
Frederick, J. R., J.A. Seydel, and R.C. Fairchild, “Improved Ultrasonic Non-Destructive Testing of Pressure Vessels,” Progress Report, NUREG-0007-1, NRC-5; University of Michigan, Mechanical Engineering Department, August 1974–July 1975.
Gebhardt, W., “Improvement of Ultrasonic Testing by Phased Arrays,” Nuclear Engineering and Design, Vol. 76, No. 3, 1983, pp. 275–283.
Holmes, Caroline, Bruce W. Drinkwater, and Paul D. Wilcox, “Post-Processing of the Full Matrix of Ultrasonic Transmit–Receive Array Data for Non-Destructive Evaluation”, NDT&E International, Vol. 38, No. 8, 2005, pp. 701–711.
Holmes, C., B. Drinkwater,, and P. Wilcox, “The Post-Processing of Ultra-sonic Array Data Using the Total Focusing Method,” Insight, Vol. 46, No. 11, 2004, pp. 677–680.
Kino, G. S., P.M. Grant, P.D. Corl, and C.S. De Silets,, “A Digital Synthetic Aperture Acoustic Imaging for NDE,” IEEE Ultrasonics Symposium Proceedings, 1978, pp. 459–467.
Lines, David I. A., J. Wharrie, and J. Hottenroth, “Real-time Full Matrix Capture + Total Focusing and Other Novel Imaging Options Using General Purpose PC-based Array Instrumentation,” Insight, Vol. 54, No. 2, 2012, pp. 86–90.
Müller, W., V. Schmitz, and G. Schäfer,, “Reconstruction by the Synthetic Aperture Focussing Technique (SAFT),” Nuclear Engineering and Design, Vol. 94, No. 3, 1986, pp. 393–404.
Ogilvy, J.A., and J.A.G. Temple, “Diffraction of Elastic Waves by Cracks: Application to Time-of-Flight Inspection,” Ultrasonics, Vol. 7, No. 6, 1983, pp. 259–269.
Olympus NDT, Phased Array Testing: Basic Theory for Industrial Applica-tions, NDT Field Guides, Waltham: Olympus Scientific Solutions Americas, 2014.
Rooney, J., and A. Reid, “Ultrasonic Inspection of Small Diameter Thin-Wall Tubing,” Ultrasonics, Vol. 4, No. 2, 1966, pp. 57–63.
Schmitz, V., S. Chakhlov, and W. Müller, “Experiences with Synthetic Aperture Focusing Technique in the Field,” Ultrasonics, Vol. 38, No. 1–8, 2000, pp. 731–738.
Shiloh, K., L.J. Bondt, and A.K. Som, “Detection Limits for Single Small Flaws and Groups of Flaws when Using Focussed Ultrasonic Transducers,” Ultrasonics, Vol. 31, No. 6, 1993, pp. 395–404.
Thomson, R.N., “Transverse and Longitudinal Resolution of the Synthetic Aperture Focusing Technique,” Ultrasonics, Vol. 22, No. 1, 1984, pp. 9–15.
Uchida, K., S. Nagaii, H. Kashiwaya, and M. Arii, “Availability Study of a Phased Array Ultrasonic Technique,” Nuclear Engineering and Design, Vol. 81, No. 2, 1984, pp. 309–314.
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