Design and the radiation patterns of rectangular symmetric bimorph piezoelectric transducers in cosinusoidal flexural vibration

Abstract

In this article, the design of rectangular symmetric bimorph piezoelectric ceramic transducers with loose and fixed edges and with parallel electric excitation is studied. Rectangular piezoelectric ceramic transducers in cosinusoidal flexural vibration with straight and parallel nodal lines of vibration are studied. The radiation of the transducer in a plane perpendicular to the surface of the transducer and parallel to the nodal lines of vibrations is examined. The radiation patterns of such transducers are evaluated using the classic theory. The radiation pattern of the transducer is evaluated in a plane, perpendicular to the direction of flexural vibration of the nodal lines. In another perpendicular plane, the radiation pattern of the transducer is calculated the same as for an oscillating piston. Diagrams to calculate these radiation patterns are supplied. For effective operation of such transducers, vibrations of the piezoelectric ceramic plate arrays with the vibrations of elastic plates, on which the arrays are mounted, must be matched. When calculating the radiation patterns of simple bimorph rectangular transducers, the expressions of the transducer’s flexural vibration mode must be evaluated. In case of multi-component rectangular transducers, the distribution of vibrations on the transducer’s surface can be evaluated as harmonic. To aid the design of a transducer with one piezoelectric ceramic plate, a diagram for calculating the width of the ceramic plate and the width of the elastic metal plate is presented.