Based on the theory of coupled vibration

the paper studied the coupling vibration modes of resonant vibration in finite diniension PZT piezoelectric ceramics disks. The relation between the radial vibration and the thickness vibration of the disks was analyzed. The frequency equation was derived theoretically. These results agree well with those of traditional theory such as the numerical methods. Experiments show that the calculated resonant frequencies are closer to the measured results compared with the results of one-dimensional vibration theory.