Coupled extensional vibrations of longitudinally polarized piezoceramic strips.

A system of one-dimensional equations for coupled length-extensional, width-stretch, and symmetric width-shear vibrations of piezoceramic strips polarized in the length direction is derived from the two-dimensional, second-order plate equations by averaging the mechanical displacement and the electrostatic potential over the strip thickness. The boundary conditions correspond to the case of electrically forced vibrations. Theoretical values are compared with results of a previous analytical model and with experimental data.

High-frequency extensional vibrations of piezoelectric ceramic bars polarized in the longitudinal direction.

The approximate 1-D governing equations for coupled length-extensional, width-stretch, and symmetric width-shear vibration modes in rectangular finite piezoelectric bars with 6 mm hexagonal symmetry are presented. The bars polarized in the longitudinal direction with electrodes on the faces perpendicular to the length are considered. The system of equations is used to study the frequency spectrum of piezoelectrically forced vibrations of bars made of hard ceramics.

Determination of the electromechanical coupling factor of gallium orthophosphate (GaPO4) and its influence on resonance-frequency temperature dependencies.

The quartz homeotype gallium orthophosphate (GaPO4) is a representative of piezoelectric single crystals of large electromechanical coupling factor. It is known that its coupling factor kappa26 associated with the resonators vibrating in the thickness-shear mode is approximately two times greater than that of quartz. This property increases the spacing between the series and parallel resonance frequencies of resonators, as well as the difference between the resonance frequency temperature dependencies of the fundamental and harmonic resonance frequencies of resonators vibrating in the thickness-shear mode.