Influence of the geometry and connection of electrodes on electromechanical characteristics of frequency-tuned disk piezoelectric elements

Amplitude-frequency and electromechanical characteristics of PZT-19 ceramic thin disk piezoelectric elements covered nonuniformly with electrodes are studied. It is shown that, in the case of in-phase connection of ring electrodes to one of the surfaces of a piezoelectric element, which enters the nonuniform stressed-strained state, mechanical vibrations can be excited at several resonance frequencies for which electromechanical-coupling coefficient k _d reaches 67% of that attained for the piezoelectric element covered completely with electrodes.