每年出版 12 期
ISSN 打印: 1091-028X
ISSN 在线: 1934-0508
Indexed in
EFFECT OF INITIAL STRESS ON THE ACOUSTIC REFLECTION FROM THE BOUNDARY OF ANISOTROPIC POROELASTIC MEDIUM WITH LIQUID
摘要
The reflection/refraction process is studied for the incidence of an acoustic wave at the interface between liquid and a fluid-saturated porous solid. The initially stressed, anisotropic porous solid saturated with viscous fluid behaves dissipatively to wave propagation. For the plane harmonic propagation, the equations of motion for a porous medium transform into a linear system of six homogeneous equations. Nontrivial solution of this system is ensured through an eighth-degree algebraic equation in vertical slowness. The roots of this equation define the propagation of eight attenuated waves in a bounded anisotropic porous medium. Four of these waves decay with distance from the boundary and are identified as refracted waves due to the incidence of an acoustic wave in a continuing liquid. Boundary conditions at the liquid-solid interface are solved in a linear system of five simultaneous equations. Five unknowns in this system define the amplitudes and phase shifts of a reflected acoustic wave and the four attenuated refracted waves. Partition of incident energy among the reflected and refracted waves is calculated as a function of the incident direction. A numerical example is solved to compute this energy partition subject to the conservation of incident energy across the interface. Amplitude and phase shift of the reflected wave vary with the direction and frequency of the incident wave. The effects of initial stress, opening of boundary pores, pore-fluid viscosity, and azimuthal anisotropy on the reflected wave are also analyzed.
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Singh Baljeet, Wave Propagation in Two-Temperature Porothermoelasticity, International Journal of Thermophysics, 41, 7, 2020. Crossref