Abstract
The paper reports an experimental investigation of the possibility of generating ultrasonic waves by a Q-switched Nd:YAG laser of small power in polymers by the example of polyvinyl chloride. The possibility of creating acoustic-point-sources in visco-elastic materials is confirmed. Explanation of the mechanism of generation of ultrasonic waves is proposed. Directivity amplitude patterns of the acoustic sources are determined using ultrasonic broadband of resonance frequencies: 1 MHz, 2.25 MHz, 5 MHz, and a head for acoustic emision. The directivity frequency pattern for a head 2.25 MHz is also determined.References
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[2] V.J. DANILOWSKAYA, Thermal stresses in an elastic half-space due to sudden heating on the surface, J. Appl. Math. Mech., 14, 316-318 (1950).
[3] R.M. WHITE, Generation of elastic waves by transient surface heating, 3. Appl. Phys., 34, 3559-3567 (1963).
[4] J. F. READY, Effects due to absorption of laser radiation, J. Appl. Phys., 36, 462-468 (1965).
[5]1 J. C. BUSHNELL and D. J. McCLOSKEY, Thermoelastic stress production in solids, J. Appl. Phys., 39, 5541-5546 (1968).
