Study On Stress Performance Of Piezoelectric Devices

Piezoelectric ceramic material has unique ability to couple electrical and mechanical displacement,so it is one of the most widely used distributed sensor and actuator in smart structures.In the application of piezoelectric ceramic sensors,mechanically induced deformations can be determined by measuring the induced electrical potential,whereas in the application of piezoelectric ceramic actuators,deformations can be controlled by introducing an appropriate electric potential.Piezoelectric ceramic bimorphs composed of passive and active layers made in elastic and piezoelectric materials respectively.They are compact and lightweight devices with high dynamic capacities which find applications in various fields as piezoelectric ceramic actuators or sensors.However,most of the researches on piezoelectric ceramic actuators focus on displacement performance,there are some problems such as insufficient research on stress properties of piezoelectric ceramic devices and shortage of stress measurement methods.In this paper,simulation analysis of the stress performance of piezoelectric ceramic devices and design of stress measurement methods are carried out.The main work includes as follows:1.The finite element models of the piezoelectric ceramic element and component were established by using ANSYS software,and their displacement and stress output characteristics were analyzed.The results show that the simulation value of the axial displacement and axial stress of piezoelectric ceramic element are basically consistent with the theoretical calculations.The output displacement and stress of piezoelectric ceramic element and component have a good linear relationship with the applied voltage.2.An analysis was performed to investigate the influence of different factors such as the geometrical dimensions and material parameters of piezoelectric ceramic element and component on their output displacement and stress performance.3.For the actual stress measurement method of piezoelectric ceramic element and component,the effects of different displacement constraints on the stress performance were studied,and a simple and feasible measurement method was designed.The simulation results show that the four-point constraint condition is the best for measuring the radial stress of the element,as well as the axial stress of the component 1,but the eight-leg constraint condition for measuring the axial stress of the component 2.4.Based on the theoretical analysis and model simulation results,a feasible stress measurement method was designed,the appropriate experimental facility was set up,and the stress of the piezoelectric ceramic element and component were measured respectively.It is proved that the piezoelectric ceramic devices with good performance can be screened by stress measurement.The reason for the difference between the experiment measured stress results and the simulated results is analyzed,and the stress measurement method was optimized.