Overview of the ETC POD Methodology

  • R. Bruce Thompson
Chapter
Part of the Review of Progress in Quantitative Nondestructive Evaluation book series (RPQN, volume 18 A)

Abstract

The probability of detection (POD) plays an integral role in the management of the lives of structural components. A number of methodologies exist for determining the POD [1]. These have been used with great success in the assessment of the detectability of surface-breaking defects such as low cycle fatigue cracks. However, a few, highly visible accidents have been caused by the rupture of rotating components of commercial jet engines due to cracks initiating from naturally occurring, internal inclusions. Difficulties have been encountered in applying existent methodologies to determine the POD of such defects for reasons such as the inability to prepare samples containing known defects which reasonably simulate naturally-occurring hard-alpha inclusions. This paper provides an overview of a new methodology that has been developed to overcome these difficulties [2–4]. The methodology also provides the advantage of providing a quantitative determination of the probability of false alarms (PFA), which quantify an important aspect of the economic costs of an inspection.

Keywords

Fatigue Titanium Rounded 

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References

  1. 1.
    “Quantitative Nondestructive Evaluation”, in Metals Handbook, Ninth Edition, Vol. 17, Nondestructive Evaluation and Quality Control, ASM, Metals Park, OH, 1989, pp. 689–701.Google Scholar
  2. 2.
    W. Q. Meeker, R. B. Thompson, C.-P. Chiou, S.-L. Jeng, and W. T. Tucker, “Methodology for Estimating Nondestructive Evaluation Capability”, Review of Progress in Quantitative NDE, 15B, pp. 1983–1991, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1996).Google Scholar
  3. 3.
    W. Q. Meeker, S.-L. Jeng, C.-P. Chiou, and R. B. Thompson, “Improved Methodology for Predicting POD of Detecting Synthetic Hard Alpha Inclusions in Titanium”, Review of Progress in Quantitative NDE, 16B, pp. 2021–2028, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1997).Google Scholar
  4. 4.
    W. Q. Meeker, S.-L. Jeng, C.-P. Chiou, and R. B. Thompson, “Improved Methodology for Inspection Reliability Assessment for Detecting Synthetic Hard-Alpha Inclusions in Titanium”,Review of Progress in Quantitative NDE, 17B, pp. 2061–2068, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY 1998).Google Scholar
  5. 5.
    C.-P. Chiou, F. J. Margetan, and R. B. Thompson, “Ultrasonic Signal Characterizations of Flat-Bottom Holes in Titanium Alloys: Experiment and Theory”, Review of Progress in Quantitative NDE, 14B, pp. 2121–2128, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1995).Google Scholar
  6. 6.
    C.-P. Chiou, F. J. Margetan, and R. B. Thompson, “Modeling of Ultrasonic Signals from Weak Inclusions”, Review of Progress in Quantitative NDE, 16A, pp. 49–55, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1997).Google Scholar
  7. 7.
    C.-P. Chiou, F. J. Margetan, and R. B. Thompson, “Development of Ultrasonic Models for Hard-Alpha Inclusions in Titanium Alloys”, Review of Progress in Quantitative NDE, 16B, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1997).Google Scholar
  8. 8.
    B. Boyd, C.-P. Chiou, R. B. Thompson, and J. Oliver, “Development of Geometrical Models of Hard-Alpha Inclusions for Ultrasonic Analysis in Titanium Alloys”, in Review of Progress in Quantitative NDE, 17A, pp. 823–830, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1998).Google Scholar
  9. 9.
    C.-P. Chiou, B. Boyd, R. B. Thompson, and J. Oliver, “Geometrical and Ultrasonic Modeling of Hard-Alpha Defect Components in Titanium Alloys”, in Review of Progress in Quantitative NDE, Vol. 18, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, in press).Google Scholar
  10. 10.
    F. J. Margetan, I. Yalda, and R. B. Thompson, “Predicting Gated-Peak Grain Noise Distributions for Ultrasonic Inspection of Metals”, in Review of Progress in Quantitative NDE, 15B, pp. 1509–1516, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1996).Google Scholar
  11. 11.
    W. Tucker and T. Keyes, private communication (to appear in an FAA technical report, published by the Technical Center, under the title of “A Methodology for Inspection Systems Capability Assessment for Subsurface Flaws in Engine Components”, currently in draft form).Google Scholar
  12. 12.
    I. Yalda, F. J. Margetan, and R. B. Thompson, “An Evaluation of the Applicability of Rician Distributions to the Addition of Ultrasonic Flaw Signals and Backscattered Noise”, in Review of Progress in Quantitative NDE, Vol. 17A, pp. 105–112, D. O. Thompson and D. E. Chimenti, Eds. (Plenum Press, NY, 1998).Google Scholar

Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • R. Bruce Thompson
    • 1
  1. 1.Center for NDEIowa State University Applied Sciences Complex IIAmesUSA

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