Article Article
Effect of Focal Law Parameters on Probability of Detection in Phased Array Ultrasonic Testing Using a Simulation and Case Study Approach

The growing energy industry has demands for high-quality, cost-effective solutions in design, fabrication, and inspection. Nondestructive testing (NDT) has always played a crucial role in the overall product integrity. Phased array ultrasonic testing (PAUT) is one of the advanced inspection technologies that promises to become the primary inspection technique for most applications in the industry. PAUT has immense inherent capabilities but, as a system, possesses controllable and uncontrollable variables, which influence its reproducibility, repeatability, and detection capability. In general, the challenge of NDT system capability is further compounded by the latest advancements in material and product diversities, which demand system validation. Validation using simulation software is likely to be a promising alternative to conventional validation techniques that utilize specimens with known reflectors. Simulation software takes into account most of the influential parameters involved during an inspection regarding the transducer, geometry, and material inspected. This paper provides outcomes on the effects of focal law parameters of PAUT on probability of detection in the aspects of detectability, resolution, and sizing of flaws. Several S-scan plans were formulated using focal parameters, including element quantity, pitch, focal depth, range of angle, and angle resolution. All of the scan plans were analyzed using simulation and practical trials to derive the best scan plan in terms of detectability, resolution, and sizing. Factors affecting the PAUT signal response due to the NDT system (probe configuration and scan plan), part (geometry and material properties), and flaw (size and orientation) were accounted for. However, other factors, including psychological and physiological human factors, were not considered. The study infers that for an effective PAUT examination, focal law parameters must be validated either through practical or simulation approach. In addition to proving the necessity of validating the focal law parameters, a simulation approach to evaluate the smallest detectable discontinuity based on effective scan plan was also done.

  • Armitt, T., “Phased Arrays Not the Answer to Every Application,” Proceedings of the 9th European Conference on Non-Destructive Testing, Berlin, Germany, 25–29 September 2006.
  • ASME, ASME Boiler and Pressure Vessel Code, Section V – Nondestructive Examination, American Society of Mechanical Engineers, New York, New York, 1 July 2015.
  • ASTM, ASTM E 2700-14, Standard Practice for Contact Ultrasonic Testing of Welds using Phased Arrays, ASTM International, West Conshohocken, Pennsylvania, 2014.
  • Birring, A.S., “Ultrasonic Phased Array for Weld Testing” Materials Evaluation, Vol. 66, No. 3, 2008, pp. 282–284.
  • Chapuis, B., F. Jenson, P. Calmon, G. DiCrisci, J. Hamilton, and L. Pomié, “Simulation Supported POD Curves for Automated Ultrasonic Testing of Pipeline Girth Welds,” Welding in the World, Vol. 58, No. 4, 2014, pp. 433–441.
  • Foucher, F., P. Dubios, V. Gaffard, H. Godinot, H. Romazzotti, A. Courbot, and E. Schumacher, “Validation of the Simulation of Pipeline Girth Welds PA UT Inspection,” ASNT Fall Conference, 29 October–1 November 2012, Orlando, Florida.
  • Ginzel, E., and D. Stewart, “CIVA Modelling for Pipeline Zonal Discrimination,”, Vol. 16, No. 4, 2011.
  • Ginzel, E., Phased Array Ultrasonic Technology, second edition, Eclipse Scientific, Waterloo, Ontario, Canada, 2013.
  • Grün, G., “Considerations About Ultrasonic Inspection of Welded Joints Using Phased Array,” 5th International Conference on Structural Integrity of Welded Structures, Timisoara, Romania, 20–21 November 2007.
  • Moles, M., “ASME Codes and Standards for Boiler Inspections,” Proceedings of the National Seminar & Exhibition on Non-Destructive Evaluation, 8–10 December 2011.
  • Moles, M., “Phased Arrays for General Weld Inspections,” 10th European Conference and Exhibition on Non-destructive Testing, Moscow, Russia, 7–11 June 2010.
  • Moles, M., “Portable Phased Array Applications,” 3rd Middle East Nondestructive Testing Conference & Exhibition, Manama, Bahrain, 27–30 November 2005.
  • Moles, M., and E. Ginzel, “Phased Arrays for Small Diameter, Thin-walled Piping Inspections,” 18th World Conference on Nondestructive Testing, Durban, South Africa, 16–20 April 2012.
  • Moran, T.L., P. Ramuhalli, A.F. Pardini, M.T. Anderson, and S.R. Doctor, “Replacement of Radiography with Ultrasonics for the Nondestructive Inspection of Welds – Evaluation of Technical Gaps – An Interim Report,” U.S. Department of Energy, April 2010.
  • Raillon, R., G. Toullelan, M. Darmon, P. Calmon, and S. Lonne, “Validation of CIVA Ultrasonic Simulation in Canonical Configurations,” 18th World Conference on Non-destructive Testing, 16–20 April 2012, Durban, South Africa.
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