Vibrations of two-layer plates of constant thickness

Within last decades laminose plates are object of numerous and various researches. Such plates represent the basic supporters of responsible engineering designs and constructions.
In many cases, the plates are not homogeneous in thickness, in particular, they are piecewise homogeneous (double layers, etc.).
At present, there is practically no theory of oscillation of piecewise homogeneous plates, and therefore the development of the theory and methods for calculating such plates is an actual problem of structural mechanics.
In given article, in a general three-dimensional formulation, we formulate the problem of the vibration of two-layered two-layer plates of constant thickness. The general rules of oscillation are derived, expressions are given for displacements and pressure at internal points of plastics through functions describing the displacements and deformations of points.