Analysis of the natural vibrations of circular piezoceramic plates with partial electrodes

The finite-element method is used to analyze the thickness-symmetric vibrations of piezoelectric plates with partial electrodes. The spectra of the natural vibrations at resonance and antiresonance, the dynamic electromechanical coupling coefficient, and the vibration modes of these plates are studied for a wide range of geometric dimensions of both the plates and the partial electrodes. The optimal dimensions of the plates and electrodes, which correspond to the maximal values of the coupling coefficient, are determined. The increase in the coupling coefficient due to the utilization of the partial electrodes is considered for piezoelectric plates made of ceramics of various compositions. It is shown that all piezoceramic compositions can be divided into two groups. For the first group, the utilization of the partial electrodes can increase the coupling coefficient of the thickness vibrations by 7–23%, depending on the vibration mode. For the second group of piezoceramics, the coupling coefficient cannot be increased in this way; in other words, complete electrodes are optimal for the thickness vibrations of plates made of piezoceramics that belongs to the second group.