The piezotransducers employed in high power ultrasound are composed of piezoelectric
ceramics and metallic pieces. These transducers are mechanically pre-stressed in order to
avoid the ceramic fractures when high voltage is applied under resonance. The resonance
and anti-resonance frequencies are shifted depending on the level of applied mechanical
pre-stressing. This paper discusses some causes of this shifting on a experimental study.
The discussion takes into account the variations on characteristic parameters of the …