Исследование методик определения констант поляризованной пьезокерамики (часть II)

Abstract

Introduction. The complete set of all ten electro-elastic moduli of the polarized ceramics essential for the analysis of piezoceramic sensing elements of various devices under the numerical solution to boundary value problems by the finite element method is considered. The work objective is to develop a new technique for determining constants of piezoelectric materials based on measuring the resonance frequencies and the first low-cycle antiresonance frequencies on one ring-like sample only. Materials and Methods. A new method of determining the full set of elastic, piezoelectric, and dielectric moduli of the polarized piezoelectric ceramics is proposed. Therewith, one sample only is used. This method is based on measuring the resonance frequencies and the first underfrequency antiresonance for an element in the form of an axial polarization ring. The first seven constants, apart from shear ones, are measured for the ring with electrodes on the ends. Shear moduli are measured on the same ring but with new electrodes on the lateral cylindrical surfaces. Old electrodes on the ends are removed. The ANSYS program implementing the finite element technique is used to validate the methodology. Research Results. For PZT4 piezoelectric ceramics, the complete set of constants defined by a new method - using only one sample - is given. The accuracy of determining the constants, as a rule, does not exceed 1%. Discussion and Conclusions. The paper presents the research results of a new valid numerical method and algorithm for determining the full set of compatible material constants of the piezoelectric ceramics on a single ring-like sample with different electrodes. The primary advantage of this method is that only one sample is used to determine the complete set of piezoceramic moduli, whereas in other methods, the measured piezoelectric moduli are not compatible since the frequencies of the resonances and antiresonances are measured at three samples different in geometry and degree of polarization.