In single-sided, two-transducer ultrasonic measurements (commonly known as acousto-ultrasonics) of composites, the received signals are useful for the nondestructive evaluation of material properties. In this paper quantitative analysis is given for the oblique echoes obtained in acousto-ultrasonic measurements on a thick uni directional composite plate. Based on the slowness surfaces of the material, angular de pendent group velocities of the various modes are computed. Experimentally measured times-of-flight of oblique echoes of quasi-longitudinal, quasi-shear-vertical, shear-hori zontal, and mode-converted waves are compared with calculated results. Excellent agree ment was obtained.
Vary, A.1988. "The Acousto-Ultrasonic Approach," in Acousto-Ultrasonics. Theory and Applicanon, J. C. Duke, Jr., ed. , Plenum Press.
3.
Duke, J.C., Jr., E.G. HenekeII, , W.W. Stinchcomb and K.L. Reifsnider1984. "Characterization of Composite Materials by Means of the Ultrasonic Stress Wave Factor," in Composite Structures 2, I. H. Marshall, ed., London: Applied Science Publishers.
4.
Govada, A., E.G. Heneke, II and R. Talreja.1984. "Acousto-Ultrasonic Measurements to Mom-tor Damage during Fatigue of Composites," in 1984 Advances in Aerospace Sciences and Engineering, U. Yuceoglu and R. Hesser, eds., New York: American Society of Mechanical Engineers.
5.
Huber, R.D. and R.E. Green, Jr.1990 "Acousto-Ultrasonic Nondestructive Evaluation of Materials Using Laser Generation and Detection," NASA Contractor Report No. 185282, NASA Lewis Research Center.
6.
Sachse, W., B. Castagnede, I. Grabec, K.Y. Kim and R.L. Weaver.1990. "Recent Developments in Quantitative Ultrasonic NDE of Composites,"Ultrasonics, 28:97-104.
7.
Auld, B.A.1973. Acoustic Fields and Waves in Solids . New York: John Wiley and Sons, see Appendix 3.
