S-wave propagation across material discontinuities in poroelasticity
| العنوان: | S-wave propagation across material discontinuities in poroelasticity |
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| المؤلفون: | Tobias M. Müller, Josue G. González, Pratap N. Sahay |
| المصدر: | GEOPHYSICS. 86:MR315-MR324 |
| بيانات النشر: | Society of Exploration Geophysicists, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Physics, Diffusion equation, Wave propagation, Poromechanics, Mechanics, Classification of discontinuities, Vorticity, Physics::Geophysics, Physics::Fluid Dynamics, Shear (sheet metal), Geophysics, Geochemistry and Petrology, S-wave, Newtonian fluid |
| الوصف: | The shear motion in Newtonian fluids, that is, the fluid vorticity, represents an intrinsic loss mechanism governed by a diffusion equation. Its description involves the trace-free part of the fluid viscous stress tensor. This part is missing in the Biot theory of poroelasticity. As a result, the fluid vorticity is not captured and only one shear wave (S-wave) is predicted. The missing fluid vorticity has implications for the propagation of S-waves across discontinuities. This becomes most apparent in the problem of S-wave propagation across the welded contact of an elastic solid with a porous medium. At such a contact, the no-slip condition between the elastic solid and the constituent parts of the porous medium, the solid frame and the pore fluid, must hold. This requirement translates into a vanishing relative motion of the fluid with respect to the solid frame, that is, the filtration field, at the contact. Nevertheless, our analysis indicates that for the Biot theory, in the low-frequency regime, a nonzero, although insignificantly small, filtration field exists at the contact. However, more importantly, the filtration field is noticeable when the transition to the high-frequency regime occurs. This constitutes a disagreement with the requirement of a no-slip boundary condition and renders the prediction unphysical. This shortcoming is circumvented by including the fluid viscous stress tensor into the poroelastic constitutive relations, as stipulated by the de la Cruz-Spanos poroelasticity theory. Then, a second S-wave is predicted that manifests as the fluid vorticity at the macroscale. This process is distinct from the fast S-wave, the other predicted S-wave akin to the Biot S-wave. We find that the generation of this process at the contact induces a filtration field equal and opposite to that associated with the fast S-wave. Therefore, the no-slip condition is satisfied and the S-wave reflection/transmission across a discontinuity becomes physically meaningful. |
| تدمد: | 1942-2156 0016-8033 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_________::837d9dc8991e9d7c98af8f6b2aa4c221Test https://doi.org/10.1190/geo2021-0284.1Test |
| رقم الانضمام: | edsair.doi...........837d9dc8991e9d7c98af8f6b2aa4c221 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 19422156 00168033 |
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