Equivalent Electrical Simulation of High -Power Ultrasonic Piezoelectric Transducers by Using Finite Element Analysis

Finite element method (FEM) has been employed extensively for vibration modal analysis of piezoelectric transducers and devices. In recent years, there has been a growing interest in the simulation and analysis of piezoelectric transducers by using equivalent electrical circuit models. This paper has been devoted to such approach for two designed and fabricated ultrasonic sandwich transducers having longitudinal vibrations for high power applications. By using analytical analysis, the dimensions of components of two high power ultrasonic transducers, which are widely used in ultrasonic welding and cleaning, were determined for the assumed resonance frequencies of 22 KHz and 30 KHz, respectively. By using a 2D finite element model, and regarding two different modeling techniques for the transducers and by application of a current source which was connected directly to the models, transient and harmonic analysis was performed by ANSYS for extraction of resonance and anti-resonance frequencies as well as voltage, current and equivalent impedance variations. Finally, simulation and experimental results were compared.