Flexural waves transmitted by rectangular piezoceramictransducers

Abstract

Rectangular piezoceramic transducers are widely used in ultrasonicevaluation and health monitoring techniques and structural vibration controlapplications. In this paper the flexural waves excited by rectangulartransducers adhesively attached to isotropic plates are investigated. In viewof the difficulties in developing accurate analytical models describing thetransfer characteristics of the transducer due to the complexelectromechanical transduction processes and transducer-structureinteractions involved, a combined theoretical-experimental approach isdeveloped. A multiple integral transform method is used to describe thepropagation behaviour of the waves in the plates, while a heterodyne Dopplerlaser vibrometer is employed as a non-contact receiver device. This combinedtheoretical-experimental approach enables the efficient characterization ofthe electromechanical transfer properties of the piezoelectric transducerwhich is essential for the development of optimized non-destructive evaluationsystems. The results show that the assumption of a uniform contact pressuredistribution between the transducer and the plate can accurately predict thefrequency spectrum and time domain response signals of the propagating wavesalong the main axes of the rectangular transmitter element.