埋入式压电陶瓷厚度对激励声能影响的有限元分析

将压电陶瓷埋入混凝土构成压电埋入式混凝土机敏模块,利用压电陶瓷的逆压电效应实现对混凝土结构的实时健康检测。为保证接收信号质量,采用具有压电陶瓷谐振频率的周期脉冲作为激励。而不同厚度的压电陶瓷具有不同的谐振频率,对于不同厚度的压电陶瓷,激励频率的选择对接收端的超声波信号有较大影响。通过Ansys软件仿真研究压电陶瓷谐振频率随厚度的变化规律,模拟混凝土中压电陶瓷振动辐射的超声波,分析压电陶瓷厚度对辐射超声波的影响。研究表明:压电陶瓷的振幅随厚度的增加逐渐减小;压电陶瓷的厚度小于1 mm时,最大振幅对应的谐振频率变化趋势出现多个拐点;厚度大于1 mm时,谐振频率随着厚度的增加而减小,辐射超声波中心点声压随厚度的增加而增大。

The Finite Element Analysis on the Influence of the Thickness of the Embedded PZT Ceramic to the Energy of Acoustic Signal

Using the inverse piezoelectric effect of piezoelectric ceramic which is embedded in concrete, we can make the real-time detection for the health of concrete structure. To guarantee the quality of received signal at the receiver, using the periodic pulse with the resonant frequency of piezoelectric ceramic to inspire the piezoelectric ceramic. But the piezoelectric ceramic with different thickness has different resonant frequency. Using Ansys software to study the influence of thickness of piezoelectric ceramic to the resonant frequency. Making the simulation research of the ultrasonic beamed by piezoelectric ceramic to research the influence of thickness of piezoelectric ceramic to ultrasonic. Experiments showed that the rule of resonant frequency would have several inflection points when the thickness of piezoelectric ceramic was less than 1 millimeter. For the piezoelectric ceramic, the thickness of which was greater than 1 millimeter, if the thickness kept increasing, the maximum vibration amplitude of piezoelectric ceramic would decrease, and the resonant frequency would also decrease, using the resonant frequency of piezoelectric, with different thickness, to inspire the corresponding piezoelectric ceramic, the maximum sound pressure of ultrasonic at the point of center beamed by piezoelectric ceramic would increase with increasing the thickness of piezoelectric ceramic.