Theoretical And Experimental Research On Mechanical Model Of Peiezoelectric Ceramic Actuators

In recent years, piezoelectric ceramic (such as Lead Zirconate Titanate, PZT) with advantages of small size, fast response, wide responding frequency and great output force are widely used as multi-purpose actuators. Through studying the physical and mechanical properties of PZT material, an equivalence principle based on the mechanical model of the PZT actuator performance was established, resulting in making it more intuitive description and simply applying the actuating properties of the PZT in engineering.Due to the special aspects of PZT piezoelectric effect, the research and application for the PZT actuator have rapidly developed. In previous research, the theory of PZT actuator usually used static method which made a coupling between the piezoelectric ceramic plate and the substrate, assuming that the strains at the contact surface of the PZT actuator and the structure are equal during calculation. However, the theory did not take into account both the dynamic characteristics of PZT material and the influence of the bond layer. Therefore, the previous theory about the modeling of PZT actuator needs to be further developing. By combining PZT dynamic ideas and the inverse piezoelectric effect, the different vibration modes of PZT mechanical model were created and further research on the mechanical properties of the PZT actuator using the developed model was conducted in the paper. The developed model for the PZT actuating performance was simple and convenient for engineering application, which was of certain significance in both theory and application.In this paper, the combination of theoretical analysis and experimental research was used and the main contents were as follows:(1) The research background, purpose and significance of the paper were firstly introduced, and the basic knowledge of smart materials and their wide application in the field of actuators were also briefly introduced.(2) The physical and mechanical properties of piezoelectric ceramics were further researched. The actuating mechanism for the PZT actuators was carefully developed and the piezoelectric equations which were one of bases for the theoretical analysis were also introduced in detail.(3) An actuating model for the embedded-type PZT actuators was established. A PZT equivalent mechanical model was set up by the lumped mass method through the research on the converse piezoelectric effect of piezoelectric ceramics. A numerical example was used to numerically analyze by using the Matlab / Simulink software. The results of the numerical simulation showed that the input and output signals of the PZT actuators had a linear relationship, and the geometry of the PZT patch and the input signal frequency as well as the cohesive layer had influenced on the output of the PZT actuators.(4) A mechanical model for the paste-type PZT actuators was established. An equivalent mechanical model for the PZT actuators was set up by using the principle of equivalence and elastic dynamic theory. A parameter analysis for the developed model was conducted by using the Matlab / Simulink software, and the influence for the thick of the bonding layer and the material performance on the output characteristics of the PZT actuators was further developed.(5) The developed paste-type model of the PZT actuator and the impact for the cohesive layer on the actuating force of the PZT driver were validated by experiments. The experimental results and that of the theoretical analysis matched well, it showed that the proposed model for the PZT actuator was reasonable and had some versatility.(6) The main work was summarized at the end and some conclusions were made, and the future research contents were also recommended.