ABSTRACT The relationships between coefficients of electromechanical coupling (CEMC) of various types of piezoceramic resonator (PR) vibrations are considered. Being constant for a given piezoceramic state, the range of variation of piezoceramics dielectric permittivity from a mechanically ``free'' condition at relatively low frequencies up to an ``overall clamped'' condition at high frequencies is determined by a consecutive ``clamping'', caused by a complex of CEMCs of various particular vibrational modes peculiar to the resonator. As the difference between ``free'' and ``overall clamped'' permittivities is always determined by the maximal piezomaterial ki3 coupling coefficient, the difference does not depend on the path that was gone through the low--high frequency range, which includes all the vibrational modes possible for a particular PR. The influence of the piezoelectric and elastic anisotropy of lead-zirconate-titanate (PZT) piezoceramic materials on relative CEMC variations was experimentally investigated.
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