Controllability of Electroacoustic Wave Process

Abstract

Usually, the electroacoustic state in a piezoelectric is described by four characteristics of coupled physical fields, and at first glance, it seems that the controllability of the process should require four control actions. However, the quasi-static approach to electroelastic processes makes it possible to use two independent influences out of four characteristics that describe the dynamic state. Another important feature in the problems of controllability of electroacoustic processes is the possibility of non-contact action on the surface of a piezoelectric medium. With the help of temporary fluctuations of the electric field (exposure to the surface of the medium by an electric field), it is possible to create equivalent mechanical stresses on the surface of the piezoelectric body. The problem of controlling the wave formation and propagation of electroactive transverse waves in a piezoelectric waveguide by non-contact surface action of an electric potential is solved. In the quasi-static formulation of the control problem for the formation and propagation of an electroelastic wave, the initial and final conditions are specified only for elastic shear. Applying the method of expansion of functions into Fourier series, the boundary value problem is reduced to an infinite system of control problems for the formation and propagation of eigenmodes of electroactive waves using harmonics of surface action. Solving an infinite system of differential equations, we find the surface control function and the true harmonic of the waveform oscillations, which translates the wave surface from a known initial state to a given final state.