N.S.Gorodetskaya, V.T.Grinchenko Analysis of physical features of the edge resonance phenomenon in elastic bodies |
Acoustic bulletin, Vol. 7 ¹ 1, (2004) |
| The features of the edge resonance are analyzed for symmetric vibrations of a semi-layer with the free edge at various Poisson's ratios. It is shown that when the Poisson's ratio changes from 0 to 0.5 the frequency of the edge resonance Ωe increases from 1.99 to 2.61. At the same time, the quality factor sharply decreases. Considering the first propagating wave as a superposition on primary and secondary waves, we note that on the edge resonant frequency the secondary wave propagates on lateral surfaces of the semi-layer, while the primary wave is an evanescent one. At frequency Ω2=2.2 practically for all Poisson's ratios the integer number of the secondary (SV) half-waves confines to width of the semi-layer (σyy(±1,z)=0). For moderate values of the Poisson's ratios 0.22<η<0.42 the frequency range exists, for which the secondary wave falls to the free edge under supercritical angle, and the primary wave (P) becomes the propagating one. For this case also the frequency Ωe1 exists, for which σyy(±1,0)=0 (accounting for SV- and P-waves). For moderate Poisson's ratios the edge resonant frequency lays between Ω2 and Ωe1. |
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KEY WORDS: the edge resonance, semi-layer with the free edge, propagating wave, evanescent wave, the Poisson's ratio |
| TEXT LANGUAGE: Russian |