Elastic moduli and dissipative properties of microinhomogeneous solids with isotropically oriented defects

Elastic properties and sound absorption in a solid containing isotropically oriented highly compliant microinhomogeneities are theoretically analyzed. The suggested model describing microinhomogeneous media can be applied to a wide class of materials, such as rocks, concretes and other solids with similar microinhomogeneous structure. Using the model, expressions for the elastic moduli, the Poisson ratio and the decrements for the longitudinal, the Young (rod) and the transversal elastic waves in isotropic microinhomogeneous materials are derived. Inter-relations of the microstructure of the solid, its elastic and dissipative properties are analyzed. The results allow for prediction of the absorption in the material and of the complementary change of its elastic parameters without detailed knowing of viscoelastic properties of the defects. The obtained conclusions are shown to be in a good agreement with existing phenomenological theoretical approximations and with known experimental data on elasticity/attenuation in rocks and in some other microstructured solids.