Investigation of the Anisotropic Nature of Laser Generated Ultrasound in HCP Crystals and Unidirectional Carbon Epoxy Composites
Abstract
Laser generated ultrasound has been used to determine material properties and to characterize material defects [1–3]. To a large extent, the success of laser ultrasonics has been the researcher’s ability to correctly predict the temporal evolution of the displacement waveform resulting from pulsed laser irradiation. Theories that assume isotropic elastic properties work well for crystalline materials that have grain sizes that are small compared to the wavelength of the interrogating ultrasonic wave [4–5]. For single crystal samples or carbon epoxies, the elastic anisotropic nature must be taken into account. Royer and Dieulesaint [6] have shown, using a plane wave analysis, that the behavior of single crystal materials in the presence of an ultrasonic disturbance differ markedly from their isotropic counterparts. In particular for cubic and tetragonal systems, Royer and Dieulesaint [6] demonstrated that the decay rate of the Rayleigh wave disturbance varies strongly as a function of the anisotropy factor.
Keywords
Line Source Transverse Isotropy Single Crystal Material Isotropic Half Space Slowness CurvePreview
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References
- 1.C.B. Scruby, R.J. Dewhurst, D.A. Hutchins, and S.B. Palmer, Research Techniques in Nondestructive Testing, (Academic, New York, 1982), 5, p 281.Google Scholar
- 2.C.B. Scruby, R.L. Smith, and B.C. Moss, NDT Int., 19, 307 (1986).CrossRefGoogle Scholar
- 3.K. Telschow, Review of Progress in Quantitative Nondestructive Evaluation, (Plenum, New York, 1988), Vol. 7b, p. 1211.Google Scholar
- 4.L.R.F. Rose, J. Accoust. Soc. Am., 73, 723, (1984)CrossRefGoogle Scholar
- 5.K.L. Telschow and R.J. Conant, J. Acoust. Soc. Am., 88, 1494 (1990).CrossRefGoogle Scholar
- 6.D. Royer and E. Dieulesaint, J. Appl. Phys., 56, 2507 (1984)CrossRefGoogle Scholar
- 7.H. Lamb, Phil. Trans. Roy. Soc. A 203, 1 (1904)CrossRefGoogle Scholar
- 8.Kraut, E.A., Rev. Geophys., 1, 401 (1963)CrossRefGoogle Scholar
- 9.Burridge, R., Q. J. Mech. Appl. Math. 24, 81, (1971)CrossRefGoogle Scholar
- 10.Willis, J.R., ‘Modern Problems in Elastic Wave Propagation,’ New York, John Wiley & Sons (1978)Google Scholar
- 11.Musgrave M.J.P. and Payton R.G., Q.J1. Mech. Appl. Math. 35, 173 (1982)CrossRefGoogle Scholar
- 12.Payton R.G., ‘Elastic Wave Propagation in Transversely Isotropic Media,’ The Hague, Martinus Nijhoff (1983)Google Scholar
- 13.Cagniard, L., ‘Reflection and Refraction of Prog. Seismic Waves,’ New York, McGraw-Hill (1962)Google Scholar
- 14.Pekeris, C.L., Proc. Natn. Acad. Sci., 41, 629 (1955)CrossRefGoogle Scholar