Inference of Fatigue Crack Closure Stresses from Ultrasonic Transmission Measurements
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The nondestructive determination of stress is usually attempted by measuring stress (or strain) related changes in material properties. Included are direct x-ray measurements of lattice constants and indirect inferences of stress or strain from changes in ultrasonic velocities or magnetic properties. However, in problems in which one wishes to determine localized stresses across an interface between two materials, neither approach is satisfactory. X-rays typically measure surface stresses and do not sample the stress condition near an internal interface. Ultrasonic velocity measurements and magnetic measurements can sense interior conditions, but also average over the properties of the intervening material. Hence, they cannot determine the localized stresses at the interface without sophisticated data reduction techniques such as those employed in holographic reconstructions.
KeywordsFatigue Crack Crack Closure Ultrasonic Velocity Closure Stress Ultrasonic Transmission
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- 2.R. B. Thompson, “A quasi-static model for the interaction of elastic waves with a planar array of voids,” unpublished technical report of Rockwell International Science Center (1973).Google Scholar
- 3.G. A. Alers and L. J. Graham, “Reflection of ultrasonic waves by thin interfaces,” 1975 Ultrasonics Symp. Proc., (IEEE, New York, 1975), pp. 579–582.Google Scholar
- 4.G. A. Alers and R. B. Thompson, “Application of trapped modes in layered media to the testing of adhesive bonds,” 1976 Ultrasonics Symp. Proc. (IEEE, New York, 1976), pp. 138–142.Google Scholar
- 5.R. B. Thompson, B. J. Skillings, L. W. Zachary, L. W. Schmerr, and O. Buck, “Effects of crack closure on ultrasonic transmission,” Review of Progress in Quantitative Nondestructive Evaluation 2, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, in press).Google Scholar
- 6.N. F. Haines, “The theory of sound transmission and reflection at contacting surfaces,” Report RD/B/N4711 (Central Electricity Generating Board, Research Division, Berkeley Nuclear Laboratories, Berkeley, England, 1980).Google Scholar
- 7.A. B. Wooldridge, “The effects of compressive stress on the ultrasonic response of steel-steel interfaces and of fatigue cracks,” Report NW/SSD/RR/42/79 (Central Electricity Generating Board, Northwestern Region, Manchester, England, 1979).Google Scholar
- 8.A. B. Wooldridge, “The effects of compressive stress and contaminating liquids on the ultrasonic detection of fatigue cracks,” Revue du Cethedec, 17eannee, 4etrimestre 1980-NS80–2, 233–244 (1980).Google Scholar
- 9.O. Buck, B. J. Skillings, and L. K. Reed, “Simulation of closure: Effects on crack detection probability and stress distributions,” Review of Progress in Quantitative Nondestructive Evaluation 2, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, in press).Google Scholar
- 14.R. B. Thompson and C. Fiedler, “Effects of crack closure on the transmission and mode conversion of ultrasonic waves,” to be submitted to J. Nondestructrive Evaluation.Google Scholar
- 15.D. O. Thompson, D. K. Rehbein, B. J. Skillings, and J. F. Smith, “Inference of compressive stresses at joined interfaces using ultrasonic reflectivity,” these proceedings.Google Scholar
- 16.S. Golan, “Measuring of closure forces with ultrasonic diffracted waves,” in New Procedures in Nondestructive Testing, P. Holler, ed. (Springer-Verlag, Berlin, in press).Google Scholar