一种用于大坝混凝土声层析成像的水听器线阵

Development of hydrophone line array for ultrasonic computed tomography in dam concrete

声层析成像技术可以用图像的方式精确完整地反映层析面上检测体内部质量,是一种有效的无损检测手段,在大坝混凝土的安全隐患检测中发挥着越来越重要的作用。本研究旨在研制成像用的接收声波的水听器线阵,该水听器线阵由12个水听器阵元组成,阵元间隔2 m,水听器由直径40 mm的接收型压电圆管和前置放大器组成。水听器在低于20 k Hz的频率范围内,自由场接收电压灵敏度为-173±3 d B,在2 MPa静水压力下灵敏度下降不超过2 d B。制作了2例具有清晰接收波形、一致性和可靠性好的水听器线阵,最终为客户在现场实地获得了高质量的层析图像。

Acoustic computed tomography （CT） can reflect the quality of tested across section in an object precisely and integrally as one of effective non-destructive test methods. In the paper, we investigated the hydrophone line array for imaging of received acoustic waves, which was composed of 12 hydrophone units, the distance between adjacent hydrophones is 2 meters. The hydrophone was composed of a diameter 40 mm receiving piezoelectric tube and a preamplifier. In the frequency range below 20 kHz, the free field receiving voltage sensitivity of hydrophone is -173 ~ 3 dB. Under hydrostatic pressure of 2 MPa, the receiving voltage sensitivity falls less than 2 dB. The 2 sets of hydrophone line arrays with clear reception waveform, good consistency and high reliability had been produced, finally the high quality tomography images were obtained for customers on-site field.