Finite element analysis of piezoelectric transducers

A finite element technique for modeling the vibrational behavior of arbitrarily shaped piezoelectric transducers immersed in an acoustic fluid is presented. The elastic and electrical responses of the piezoelectric structure are computed by piezoelectric finite elements, and the wave propagation in the ambient acoustic medium is computed by acoustic finite elements. The acoustic feedback of the surrounding acoustic fluid to the piezoelectric solid is considered. This method makes it possible to analyze piezoelectric devices with respect to their mechanical strains and stresses, electrical fields and displacements, and various integral properties, such as the electric input impedance and the electromechanical coupling coefficient. The application of this method to ultrasonic transducers, especially those used in array antennas, is reported