Abstract
A measurement model has been developed to describe ultrasonic measurements made with circular piston transducers in parts with flat or cylindrically curved surfaces. The model includes noise terms to describe electrical noise, scatterer noise and echo noise as well as effects of attenuation, diffraction and Fresnel loss. An experimental procedure for calibrating the noise terms of the model was developed. Experimental measurements were made on a set of known flaws located beneath a cylindrically curved surface. The model was verified by using it to correct the experimental measurements to obtain the absolute scattering amplitude of the flaws. For longitudinal wave propagation within the part, the derived scattering amplitudes were consistent with predictions at internal angles of less than 30°. At larger angles, focusing and aberrations caused a lack of agreement; the model needs further refinement in this case. For shear waves, it was found that the frequency for optimum flaw detection in the presence of material noise is lower than that for longitudinal waves; lower frequency measurements are currently in progress. The measurement model was then used to make preliminary predictions of the best experimental measurement technique for the detection of cracks located under cylindrically curved surfaces.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
J.A. Harris, Jr., D.L. Sims, C.G. Annis, Jr., “Concept Definition, Retirement for Cause of F100 Rotor Components, ” AFWAL-TR-80-4118, 1980.
H. Wustenberg, “Fokussierende Prufkopfe zur Verbesserung der Fehlergrossenabschatzung bei der Ultrasschallprufung von Dickwandigen Reaktor Komponenten,” Material Prufung 18, 154, 1976.
R.B. Thompson and T.A. Gray, “Analytical Diffraction Correction to Ultrasonic Scattering Measurements,” these proceedings.
J.L. Opsal, “Elastic Wave Scattering from Voids and Cracks with Rough Surfaces,” unpublished.
G.C. Benson and O. Kiyohara, J. ASA 55, January 1974.
R.K. Elsley, “Accurate Ultrasonic Measurements with the Biomation 8100 Transient Recorder,” NBS Special Publication 596, U.S. Dept of Commerce, 1980.
B.R. Tittmann and L.A. Ahlberg, “Attenuation and Grain Noise Parameters,” these proceedings.
K.W. Fertig and J.M. Richardson, “Computer Simulation of Probability of Detection,” these proceedings.
R.C. Addison, R.B. Huston, J.F. Martin and R.B. Thompson, “Test Bed for Quantitative NDE,” Proc. of DARPA/AF Review of Progress in NDE, Air Force Report (AFML-TR-80-4078).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1983 Plenum Press, New York
About this chapter
Cite this chapter
Elsley, R.K., Addison, R.C., Graham, L.J. (1983). Detection of Flaws Below Curved Surfaces. In: Thompson, D.O., Chimenti, D.E. (eds) Review of Progress in Quantitative Nondestructive Evaluation. Library of Congress Cataloging in Publication Data, vol 2A. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-3706-5_7
Download citation
DOI: https://doi.org/10.1007/978-1-4613-3706-5_7
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-3708-9
Online ISBN: 978-1-4613-3706-5
eBook Packages: Springer Book Archive