Yu.A.Kosevich, E.S.Syrkin Surface absorption and resonant interaction of elastic waves with two-dimensional defect |
Acoustic bulletin, Vol. 3 ¹ 3, (2000) |
| Resonant interaction of a bulk acoustic phonon with planar defect in a solid with an account for the bulk and surface absorption is considered. The interaction is described with inhomogeneous two-dimensional elastic layer having the internal dynamical degree of freedom, and with homogeneous planar defect. It is shown that resonant reflection of bulk transverse phonon at homogeneous two-dimensional defect, caused by interaction with deeply penetrating leaky wave, is very sensitive to the acoustic absorption, especially to the bulk one. We obtained the restrictions on maximum possible values of dissipative parameters of the medium when the strong reflection of a bulk transverse phonon at homogeneous two-dimensional defect occurs. It is shown that the interaction of a bulk phonon with the resonant mode of inhomogeneous two-dimensional layer, which results in acoustical clearing of the interface, is less sensitive to the bulk acoustic absorption because deeply penetrating leaky wave is not excited at the interface in this case. Anomalously strong surface absorption of a bulk transverse phonon is predicted when one half of the incident acoustic energy is absorbed at two-dimensional defect as a consequence of interaction with deeply penetrating leaky wave. |
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KEY WORDS: phonons, a planar defect, resonant interaction, surface absorption, leakage wave |
| TEXT LANGUAGE: Russian |