On attenuation in layered porous Biot media and their effective models

The effective models of periodic layered porous Biot media possessing viscosity and relaxation are established and investigated. These models correspond to the generalized Biot media with the equations containing as a rule exponential kernels of relaxation and viscosity. There exist such kernels even if in the initial medium relaxation is absent. The inequalities, which must be satisfied by the parameters of kernels, are established by means of the energy investigations. The partial cases when the effective models possess no viscosity or no relaxation are pointed out.