ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

5aPAa8. Acoustic wave processes in viscoelastic porous media.

Timothy S. Margulies

Natl. Ctr. for Physical Acoust., Univ. of Mississippi, Oxford, MS 38677

An understanding of acoustic waves in deformable, porous media has important applications in understanding propagation characteristics through ocean sediments, as well as, in the seismicity of rocks and earthquake design. Continuum balance equations for viscoelastic mixtures are applied to wave dynamics of fluid flow in porous media. Stress representations for the response of the solid phase, for example, Kelvin-Voigt are assumed and compared to frame-indifferent fractional calculus stress tensor assumptions. The linear plane-wave dynamics are developed for homogeneous materials and inhomogeneous layered porous media using matrix propagator techniques. Several specific examples and concluding remarks on possible future directions for theoretical and experimental investigations will be given to gain a better understanding of the effects of coupled deformable solid and fluid motions, in addition to relaxation effects such as chemical reactions or multiphase mass-transfer processes.