Abstract
An analytical model on electromechanical coupling coefficient and the length optimization of a bending piezoelectric ultrasonic transducer are proposed. The piezoelectric transducer consists of 8 PZT elements sandwiched between four thin electrodes, and the PZT elements are clamped by a screwed connection between fore beam and back beam. Firstly, bending vibration model of the piezoelectric transducer is built based on the Timoshenko beam theory. Secondly, the analytical model of effective electromechanical coupling coefficient is built based on the bending vibration model. Energy method and electromechanical equivalent circuit method are involved in the modelling process. To validate the analytical model, sandwich type piezoelectric transducer example in second order bending vibration mode is analysed. Effective electromechanical coupling coefficient of the transducer is optimized with simplex reflection technique, and the optimized ratio of length of the transducers is obtained. Finally, experimental prototypes of the sandwich type piezoelectric transducers are fabricated. Bending vibration mode and impedance of the experimental prototypes are tested, and electromechanical coupling coefficient is obtained according to the testing results. Results show that the analytical model is in good agreement with the experimental model.
Highlights
The developments of computer science and new software techniques have greatly promoted the designing, optimization, and characterization of piezoelectric ultrasonic transducers, there are still lots of problems existing in piezoelectric ultrasonic transducer technology over the past few decades
In contrast to the previous works, we find that the electromechanical coupling models for the beam-like sandwich type piezoelectric ultrasonic transducers have seldom been noticed
Bending vibration model of sandwich type piezoelectric transducer is first built based on Timoshenko beam theory
Summary
The developments of computer science and new software techniques have greatly promoted the designing, optimization, and characterization of piezoelectric ultrasonic transducers, there are still lots of problems existing in piezoelectric ultrasonic transducer technology over the past few decades. An enhanced equivalent circuit model of a rotary traveling wave piezoelectric USM is derived by El Ghouti and Helbo [14] They highlight the importance of the electromechanical coupling coefficient, which is responsible for the electrical to mechanical energy conversion. In contrast to the previous works, we find that the electromechanical coupling models for the beam-like sandwich type piezoelectric ultrasonic transducers have seldom been noticed. This type of transducer is widely used in many applications. The objective of the present work is to derive the analytical model of effective electromechanical coupling coefficient by extracting the parameters from the electromechanical equivalent circuit representing the sandwich piezoelectric ultrasonic transducer and find out the length optimization which can guide the designing of the transducer. Validation of the analytical model is conducted by fabricating the prototype transducers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
