Homogenizing the acoustic properties of the seabed, part II

  • Authors:
  • Th. Clopeau;J. L. Ferrín;R. P. Gilbert;A. Mikeli

  • Affiliations:
  • Analyse Numérique, CNRS UMR 5585 Bât. 101, Université Lyon 1 43, Bd. du onze novembre, 69622 Villeurbanne Cedex, France;Departament de Matemática Aplicada Universidad de Santiago de Compostela 15706 Santiago de Compostela, Spain;Department of Mathematical Sciences University of Delware Newark, DE 19716, U.S.A.;Analyse Numérique, CNRS UMR 5585 Bât. 101, Université Lyon 1 43, Bd. du onze novembre, 69622 Villeurbanne Cedex, France

  • Venue:
  • Mathematical and Computer Modelling: An International Journal
  • Year:
  • 2001

Quantified Score

Hi-index 0.98

Visualization

Abstract

We undertake a rigorous derivation of the diphasic Biot's law, describing small deformations of a seabed of the characteristic size L"0/@e^2 and containing a pore structure of the characteristic size @e. The solid part of the seabed (the matrix) is elastic and the pores contain a viscous fluid. The fluid is supposed incompressible or slightly compressible. In this case, the contrast of property is of order @e^2, i.e., the normal stress of the elastic matrix is of the same order as the fluid pressure. We suppose a periodic matrix and obtain the a priori estimates. Then we let the characteristic size of the inhomogeneities tend to zero and pass to the limit in the sense of the two-scale convergence. The obtained effective equations represent a two-scale system for three velocities and two pressures. We prove uniqueness for the homogenized two-scale system. Then we introduce several auxiliary problems and obtain a problem without the fast scale. This new system is diphasic and corresponds to the diphasic effective behavior already observed in papers by Biot. In the effective equations, it is possible to distinguish the velocities of the fluid and the solid part, respectively. The effective stress tensor contains an instantaneous elasticity tensor and there are double porosity terms. We give a detailed study of the effective equations and compare them with the original Biot's poroelasticity equations.