中文摘要：

将PZT作为声源埋人混凝土中构成的混凝土压电机敏模块具有超声检测功能。对埋人该模块中的PZT圆片模态分析发现，在各阶振动模态下PZT声辐射面存在分布不同的振幅极大值区域。基于混凝土压电机敏模块的声场指向性和声能实验表明：将PZT声辐射面等效为振幅相等的单一点声源的叠加，忽略振动模态对声场指向性影响，使得PZT圆片的声场指向性随频率变化规律偏离实际较大，而且在相同频率下声场指向性理论结果比实验结果发散；在各阶固有频率激励下，PZT圆片的声场指向性集中，但在一阶固有频率下声能最高，更适用于超声检测。

英文摘要：

The smart concrete module embedded PZT seen as acoustic source is with ultrasonic detection function. Model analysis of PZT wafer shows different maximum multitude distribution on the wafer acoustic radiating surface. The experiment based on smart concrete module shows while the radiating surface seen as superposition of equal multitude single point source and ignoring the vibration mode, the acoustic directivity variation deviates from the actual with frequency, and the directivity becomes divergent at a frequency. The first natural frequency is more suitable for ultrasonic detection considering the acoustic directivity and energy.