ACOUSTOELASTICITY THEORY AND APPLICATIONS FOR FLUID-SATURATED POROUS-MEDIA

The general theory for small dynamic motion superimposed upon large st atic deformation, or acoustoelasticity, is developed for isotropic flu id-filled poroelastic solids. Formulas are obtained for the change in acoustic wave speeds for arbitrary loading, both on the frame and the pore fluid. Specific experiments are proposed to find the complete set of third-order elastic moduli for an isotropic poroelastic medium. Be cause of the larger number of third-order moduli involved, seven as co mpared with three for a simple elastic medium, experiments combining o pen-pore, closed-pore, jacketed, and unjacketed configurations are req uired. The details for each type of loading are presented, and a set o f possible experiments is discussed. The present theory is applicable to fluid-saturated, biconnected porous solids, such as sandstones or c onsolidated granular media. (C) 1996 Acoustical Society of America.