Performance of piezoelectric ceramic materials

PZT materials piezoelectric disk have been widely used in structural damage diagnosis and health detection due to their advantages of low cost, fast response, simple structure, and good reliability. In the 1990s, the method of on-line monitoring of the internal structure of concrete piezo-embedded .smart module is embedded in the piezo ceramic tube was proposed, which made up for the deficiency of traditional non-destructive testing. The piezoelectric ceramic is buried in the concrete was excited by periodic pulses of different frequencies. 

By analyzing the receiving ultrasonic signals, it was found that the received signal energy was maximized under the excitation of a periodic pulse of 79 kHz. However, ultrasonic piezo disk vibration sensor will produce acoustic wave diffusion and energy attenuation during the propagation process, which is resulting in the limited ultrasonic energy received at the receiving end, which is not conducive to analysis and processing. When studying the sound energy characteristics of backing structure PZT in thickness vibration mode, it was found that when the excitation frequency is in the range of 60 kHz ~100 kHz, the ultrasonic signal energy of piezo ceramic cylinderis received by the receiving end is larger, which is suitable for non-destructive testing.In addition, for different sizes of piezoelectric ceramics, there are multiple resonant frequencies, and the maximum amplitude that can be achieved is also different, and the ultrasonic signal energy of the piezoelectric ceramic vibrational radiation is related to its vibration amplitude. 

Therefore, for different sizes of piezoelectric ceramic disc crystal, studying its vibration has important practical significance for improving the utilization rate of ultrasonic waves. In this paper, finite element analysis of the vibration of piezoelectric ceramics are conducted. The corresponding resonant frequencies of piezoelectric ceramics has different sizes and the variation of the maximum amplitude with the thickness of the piezoelectric ceramic sensors are studied. The sound pressure and thickness of the ultrasonic waves are analyzed. Correspondence between them has the directionality of ultrasound in the propagation process.