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Shear horizontal surface acoustic waves and excitations on rough surfaces. (English) Zbl 0738.73016

Continuum models and discrete systems. Vol. 1, Interaction Mech. Math. Ser. 1, 277-295 (1990).
[For the entire collection see Zbl 0731.00029.]
In this paper, we consider three kinds of rough surfaces, each of which would be planar in the absence of the roughness, and investigate a surface acoustic wave or excitation specific to each kind of roughness.
In the case of a deterministic, non-periodic rough surface we study the scattering of an acoustic wave from an isolated ridge on the otherwise planar surface of a semi-infinite elastic medium, as a way of experimentally detecting the acoustic surface shape resonances supported by this structure. When the profile function \(\zeta(x_ 1)\) is a deterministic and periodic function of \(x_ 1\), i.e., when it describes a classical grating, we study the propagation of acoustic waves of shear horizontal polarization bound to the interface between two different elastic media defined by the equation \(x_ 3=\zeta(x_ 1)\). If the surface profile function \(\zeta(x_ 1)\) is a stationary, stochastic, Gaussian process, and describes the stress-free surface of a semi- infinite elastic medium, we show that a bulk acoustic wave of shear horizontal polarization incident on it from inside the medium displays the phenomenon of enhanced backscattering. This is the existence of a narrow, well-defined peak in the angular dependence of the intensity of the diffuse component of the scattered sound when the scattering is into the retro-reflection direction.

MSC:

74J15 Surface waves in solid mechanics
74A40 Random materials and composite materials
74E05 Inhomogeneity in solid mechanics

Citations:

Zbl 0731.00029
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