The piezoelectric material-concrete module is an intelligent structure of a piezoelectric unit combined with concrete into which the unit was embedded. Such module can be used to monitor the health of the concrete structure. In order to enhance the acoustic signal created by the iezoelectric material, a piece of metal backing sticks on the piezoelectric ceramic disc to construct a piezoelectric unit. The method allows the receiver on the axial direction of the embedded iezoelectric unit received the acoustic signal energy enhanced more than 10 times. We got a curve of the relative acoustic signal energy increment versus the products of backing metal thickness and the excited acoustic frequency. From the analysis of the power spectrum of acoustic signal, the thickness of the metal backing does not make change the peak power frequency and the frequency bandwidth range of the acoustic signal power spectrum.%压电埋入式混凝土敏感模块是利用在混凝土中埋入的压电陶瓷形成的一种复合式智能单元.该敏感模块可以对混凝土结构的健康状况进行检测.为了提高埋入混凝土中的压电陶瓷所激励声能的效率从而提高检测的准确性,提出了一种在压电陶瓷圆片一侧用硅橡胶层和金属背衬的方法,该方法能将压电陶瓷双侧的声能集中到一侧从而充分利用声信号能量提高声激励效率.实验表明,该方法能使接收端同距离下压电陶瓷圆片轴向声信号的能量提高10倍以上,并得到了声信号能量的相对增量随埋入混凝土中压电陶瓷一侧的背衬厚度与声激励频率之积变化的特性曲线.对声信号进行功率谱分析还表明,背衬没有改变声信号功率谱的主频和主峰区间的频率带宽.
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