Excitation method and electromechanical coupling dynamic model of a novel torsional piezoelectric actuator

Abstract

Torsional piezoelectric actuators have been widely applied in many fields due to their specific vibration mode. However, the conventional torsional vibration piezoelectric actuators require circumferentially polarized piezoelectric ceramics or special structural designs, increasing manufacturing difficulty and processing costs, and seriously limiting their applications. In order to solve these problems, a novel excitation method of torsional vibration is proposed in this study through the arrangement of the regular piezoelectric ceramic plates polarized along their thickness direction, and then two surface-bonded type torsional piezoelectric actuators are constructed to stimulate the odd and even order torsional vibration modes, respectively. A novel transfer matrix model of describing the torsional vibration, which involves in the mechanical and electrical properties, is created first for the piezoelectric composite beam element. Then a general electromechanical coupling dynamic model is developed to reveal dynamic behaviors of the proposed surface-bonded type torsional piezoelectric actuators. In addition, the finite element simulation and experimental investigations are carried out to confirm the validation of the proposed excitation method of torsional vibration and to verify the correctness of the developed electromechanical coupling dynamic model. The comparisons showed that the results calculated by the developed theoretical model, simulated by the finite element method, and tested by the experiments matched well, indicating that the developed electromechanical coupling dynamic model is correctness and the excitation method of torsional vibration is effective. Finally, the output characteristics of the two proposed actuator prototypes are measured, further confirming the feasibility of the proposed torsional vibration excitation method.