Reflection of a plane sound wave from the boundary of a heterogeneous medium consisting of elastic and viscoelastic layers

The reflection of a plane sound wave incident normally on the flat boundary of a layered heterogeneous medium is considered. The heterogeneous medium consists of periodically alternating layers of elastic and viscoelastic isotropic materials. All the layers are assumed to be parallel or perpendicular to the wavefront and each layer is much thinner than the sound wavelength. The problem is studied using a homogenized model of the layered heterogeneous medium. Specifically, the complex amplitudes of the reflected and transmitted waves are determined as functions of frequency.