Imagine finding a piece of material while out on a hike with family or friends in a local park. The material is unlike anything you have seen before and appears to be unique in the way it looks and feels. Your curiosity is triggered; what is this? Is it something of value that was lost by a previous hiker? Is it a small piece of a meteorite? Is it something a little more nefarious that requires alerting law enforcement? With a portable probe you are carrying in your pack, you touch the material and immediately a wealth of information becomes available: material type, composition, microstructure, properties, processing, history, and past use. Each value, including uncertainty bounds, provided by the portable instrument enables you to understand what you found. This approach to characterization was the basis for a line of questioning used by Robert Green of John Hopkins University (now retired) during oral qualifying exams for his doctoral students and illustrates the potential of using nondestructive testing-based (NDT) methods for quantitative characterization. When considering the above future scenario, it is important to ponder for a moment what is meant by quantitative characterization. As the topic of a special issue of Materials Evaluation, a number of readers may question if this is new and whether current practice already enables quantitative information to be obtained using NDT methods. Nondestructive testing has a rich history of use across multiple industries. It is commonly used to assure manufac-turing quality and is used extensively in the sustainment of deployed assets, including aerospace, power, oil and gas, and transportation. In addition, inspections testing is common practice and provides a key input in the safe management of assets across all industries. For the US Air Force, nondestructive inspection capability for safety-of-flight critical locations is one of approxi-mately seven inputs required for risk management (safety) of the structural integrity of aircraft managed by damage tolerance (Lindgren, 2007). With the broad-based use of NDT, a reasonable question to ask is why there is the emphasis on characterization in this issue. A direct answer is there is a growing need across multiple industries to move beyond detection, and better support both manufacturing quality assurance and sustainment with quantitative evalua-tion of the material state. Therefore, the scope of this article is to review some definitions of terminology as the same word(s) can often be used to define different things. For example, industrial users of NDT and academic researchers in the same field can infer different meanings from the same words. This will be followed by a summary of some of the main technical chal-lenges to realize quantitative characterization from the author’s perspective. This list may not be comprehen-sive and any feedback on these challenges is always welcomed. The final section of this introductory article will identify possible opportunities for research, devel-opment, and engineering to realize the desired capa-bility. Again, this list is not to be construed as comprehensive, but reflects the opinion of the author and areas that are identified as having significant impact on addressing the identified challenges.
Aldrin, J.C., H.A. Sabbagh, R.K. Murphy, E.H. Sabbagh, and J.S. Knopp, “Sensitivity Analysis of Inverse Methods in Eddy Current Pit Characterization,” Review of Progress in QNDE, Vol. 29, AIP, 2010, pp. 771–718.
Aldrin, John C., Eric B. Shell, Erin K. Oneida, Harold A. Sabbagh, Elias Sabbagh, R. Kim Murphy, Siamack Mazdiyasni, and Eric A. Lindgren, “Model-based Inverse Methods for Sizing Surface-breaking Discontinuities with Eddy Current Probe Variability,” 42nd Annual Review of Progress in QNDE: Incorporating the 6th European-American Workshop on Reliability of NDE, Vol. 1706, published online 2016a.
Aldrin, John C., David S. Forsyth, John T. and Welter, “Design and Demonstration of Automated Data Analysis Algorithms for Ultrasonic Inspection of Complex Composite Panels with Bonds,” 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation: Incorporating the 6th European-American Workshop on Reliability of NDE, Minneapolis, Minnesota, 26–31 July 2015, Vol. 1706, AIP Conference Proceedings, published online 2016b.
Banks, H.T., Jared Catenacci, and Amanda Criner, “Quanti-fying the Degradation in Thermally Treated Ceramic Matrix Composites,” International Journal of Applied Electromag-netics and Mechanics, Vol. 52, No. 1–2, 2016, pp. 3–24.
Katt, Robert J., National Academies of Sciences, Engi-neering, and Medicine, Applying Materials State Awareness to Condition-based Maintenance and System Life Cycle Management, National Academies Press, Washington, D.C., 2016.
Kobryn, Pamela A. “Digital Thread and Sustainment,” avail-able at http://meetingdata.utcdayton.com/agenda/viewab-stract.asp?aid=41933&ID=airworthiness201776816699.
Lindgren, E.A., J.S. Knopp, J.C. Aldrin, G.J. Steffes, and C.F. Buynak, “Aging Aircraft NDE: Capabilities, Challenges, And Opportunities,” Review of Progress in QNDE, Vol. 26, AIP, 2007, pp. 1731–1738.
Lindgren, Eric A., “US Air Force Perspectives on Validated NDE: Past, Present, and Future,” 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation: Incor-porating the 6th European-American Workshop on Relia-bility of NDE, Minneapolis, Minnesota, 26–31 July 2015, AIP Conference Proceedings, Vol. 1706, published online 2016.
Medina, E. A., Aldrin, J. C., Santiago, J., Lindgren, E. A., Buynak, C. F., Knopp, J. S., “Demonstration for Reliability Assessment of Structural Health Monitoring Systems Incor-porating Model-assisted Probability of Detection Approach,” Proceedings of the 7th International Workshop on Structural Health Monitoring, Ed. F.-K. Chang, Stanford, California, September 13-15, 2011, p 2460.
Nelson, Luke J. and Robert A. Smith, “Three-dimensional Fibre-Orientation Characterisation in Monolithic Carbon-Fibre Composites,” 11th European Conference on Non-Destructive Testing (ECNDT 2014), Prague, Czech Republic, 6–10 October 2014, published on Ndt.net.
OC Robotics, “RANDE - Non-destructive Inspection,” accessed on 10 May 2017 from
Panetta, Paul, Leslie Bland, Maureen Tracy, and Waled Hassan, “Ultrasonic Backscattering Measurements of Grain Size in Metal Alloys,” TMS2014 Annual Meeting Supple-mental Proceedings, TMS (The Minerals, Metals & Materials Society), 2014.
Simonetti, F., “Multiple Scattering: The Key to Unravel the Subwavelength World from the Far-Field Pattern of a Scat-tered Wave,” Physical Review E, Vol. 73, No. 3, 2006, p. 036619.
Thompson, R. Bruce, “Back to Basics: The Role of Model Based Inversion,” Materials Evaluation, Vol. 66, No. 7, 2008, pp. 707–712.
US Department of Defense, Handbook, Nondestructive Eval-uation System Reliability Assessment, MIL-HDBK-1823A, April 7 2009.
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