Vinitha:

The resonance frequency of a piezo-electric element is that in which the element can transmit or receive a major vibration energy. You can find this frequency, well by means of a frequency swept in order to localize the point in which emission/ reception attain a maximum, or well by using an impedance meter to see the maximum of Conductance or Resistance (depending of the electrical operating conditions applied to the piezoelectric device).

Regards,

Antonio

The resonant frequency, the ceramic element vibrates most readily, and most efficiently converts the electrical energy input into mechanical energy.

The values for resonant frequency and antiresonant frequency can be used to calculate the electromechanical coupling factor, k, an indicator of the effectiveness with which a piezoelectric material converts electrical energy into mechanical energy or mechanical energy into electrical energy.

The resonant frequency provides the maximum electrical harvesting solution from the vibration of a mechanical device. You can test the resonant frequency of a mechanical device by using a FFT analyzer or an impedance analyzer.

i need to improve power generation by using resonant frequency.

Dear Vinitha:

In order to improve the power generation efficiency of an ultrasonic system, it is needed to automatcally track the "series" resonant frequency of the transducer (normally, the optimal excitation frequency, under constant voltage driving), but in real working conditions, which use to be notably varying with transducer heating and other causes. To obtain this difficult aim, some type of automatic driving procedure must be used, for instance, that described in the paper:  "Automatic system for dynamic control of resonance in high power and high Q ultrasonic transducers", by the authors: (Antonio Ramos, Fausto Montoya Vitini, Juan A Gallego-Juarez). Ultrasonics 23(4):pp.151-156. 1985. DOI: 10.1016/0041-624X(85)90023, which I have annexed you in the attachment.

I hope that this paper can be of utility for your problem.

Regards

Antonio, CSIC (Madrid)