Determination of piezoelectric parameters from the measured natural frequencies of a piezoelectric circular plate

ABSTRACT

Due to the complexity of electro-elastic coupling characteristics in piezoelectric materials, some elastic, dielectric and piezoelectric parameters are difficult to measure. Usually, these parameters are determined by assuming that all other parameters remain constant during the measurement. However, the interactive effect between material properties makes this assumption not always true. In this study, the measured natural frequencies of the specified circular piezoelectric plate are used to extract these parameters simultaneously. In other words, all these parameters are determined with consideration of the interactive electro-elastic coupling effect.

The analytic model of a free-free circular piezoceramic plate was derived and solved to establish the relationship between natural frequencies and their material parameters. In order to cover most of the parameters, the out-of-plane (non-symmetric transverse) and in-plane (symmetric extensional) modes are considered.

The genetic algorithm is employed to determine most of the elastic, dielectric and piezoelectric parameters from a least square error between the calculated and measured natural frequencies. The numerical results derived from the parameters proposed in this work reveal that they coincide well with the measured data. In other words, the proposed method for extracting piezoelectric parameters is both feasible and effective.

KEYWORDS:

• Piezoelectric materials; dielectric constants; piezoelectric constants