Abstract
A method is developed to calculate ultrasonic surface waveforms generated by an extended laser source, operating in the thermoelastic regime of laser-pulse energy density. This approach integrates over a suitably weighted distribution of point surface centers of expansion, for observation to within 1 mm of the edge of the source. Power spectra as well as both horizontal and vertical displacements are presented and discussed for ultrasonic waveforms on an aluminium surface, for incident laser pulses having Gaussian lateral profiles of various sizes. Far from the source, the waveform is dominated by a dipolar Rayleigh (R) wave, whose amplitude and spectral content depend on laser spot size. Weak, monopolar pulses also occur at the intersection of bulk pressure and shear wavefronts with the surface (denoted assP andsS, respectively). Close to the source, thesP wave amplitude approaches that for theR wave, and overlaps theR wave for large source sizes. The fall-off with distance for bothsP andR waves is given. Finally, the changes in pulse shape and amplitude are calculated when anR wave from an extended thermoelastic source is reflected or transmitted by a right-angled corner of an aluminium block.
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References
R. M. White,J. Appl. Phys. 34:3559–3567 (1963).
C. B. Scruby, R. J. Dewhurst, D. A. Hutchins, and S. B. Palmer, inResearch Techniques in Nondestructive Testing, R. S. Sharpe, ed. (Academic Press, 1982), Vol. 5, Chap. 8.
L. R. F. Rose,J. Acoust. Soc. Am. 75:723–732 (1984).
A. N. Ceranoglu and Y-H Pao,J. Appl. Mech. 48:125–147 (1981).
H. N. G. Wadley, C. K. Stockton, J. A. Simmons, M. Rosen, S. D. Ridder, and R. Mehrabian, inReview of Progress in Quantitative NDE D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1982), Vol. 1, pp. 421–431.
N. N. Hsu,Dynamic Green's Functions of an Infinite Plate — A Computer Program, U.S. National Bureau of Standards Report NBSIR 85-3234, 1985.
T. M. Proctor, F. R. Breckenridge, and Y-H. Pao,J. Acoust. Soc. Am. 74:1905–1907 (1983).
H. N. G. Wadley, J. A. Simmons, and C. Turner, inReview of Progress in Quantitative NDE. D. O. Thompson and C. E. Chimenti, eds. (Plenum Press, New York, 1984), Vol. 3B, pp. 683–697.
D. A. Hutchins,Can J. Phys. 64:1247–1264 (1986).
P. A. Doyle,J. Phys. D: Appl. Phys. 19:1613–1623 (1986).
L. R. F. Rose,Wave Motion 6:359–361 (1984).
K. Aki and P. G. Richards,Quantitative Seismology Theory and Methods (Freeman, San Francisco, 1980), Vol. 1.
J. E. Ready,Effects of High-power Laser Radiation (Academic, New York, 1971).
W. Arnold, B. Betz, and B. Hoffman,Phil. Trans. R. Soc. Lond. A320:315–318 (1986).
C. M. Scala and P. A. Doyle,J. Acoust. Soc. Am. 85:1569–1576 (1989).
J. D. Achenbach, A. K. Gautesen, and H. McMaken,Ray Methods for Waves in Elastic Solids (Pitman, 1982).
C. B. Scruby and B. C. Moss, inRayleigh-wave Theory and Application, E. A. Ash and E. G. S. Paige, eds. (Springer Verlag, Berlin, 1985), pp. 102–109.
E. R. Lapwood,Geophys. J. 4:174–196 (1961).
A. K. Gautesen,J. Appl. Mech. 52:664–668 (1985).
A. K. Gautesen,Wave Motion 8:27–41 (1986).
A. K. Gautesen,Wave Motion 9:51–59 (1987).
J. A. Cooper, R. A. Crosbie, R. J. Dewhurst, A. D. W. McKie, and S. B. Palmer,IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control UFFC-33:462–470 (1986).
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Doyle, P.A. Calculation of ultrasonic surface waves from an extended thermoelastic laser source. J Nondestruct Eval 8, 147–164 (1989). https://doi.org/10.1007/BF00570884
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DOI: https://doi.org/10.1007/BF00570884