Fundamental experiment for inspection of cooling pipes in operation by using ultrasonic technique
Fundamental experiment for inspection of cooling pipes in operation by using ultrasonic technique
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DOI：
10.1016/j.fusengdes.2005.09.044
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发表时间：
2006-02
影响因子：
1.7
通讯作者：
Y. Ohtsuka;M. Higashi;M. Nishikawa
中科院分区：
文献类型：
--
作者：
Y. Ohtsuka;M. Higashi;M. Nishikawa
研究了剪切水平波传播特性作为一种识别不锈钢缺陷的方法，在核反应堆运行过程中检测缺陷的开发技术中具有潜在的应用前景。将缺陷定位在发射器和接收器之间，通过改变发射频率来改变超声波的传播角度。接下来，将来自缺陷的波形与没有缺陷的情况下的参考波形数据进行比较。结果表明，前表面缺陷的差值信号在500和700kHz处振幅最大，下表面缺陷的差值信号在560kHz处振幅最大。我们发现产生最大信号幅值的传输频率等于超声波的传播方向，即由永磁体的方向角、声速和宽度决定的频率。进一步，通过对发射和接收频率的研究，我们发现在接收频率与发射频率不同的情况下，接收频率随缺陷深度的变化而变化。
Shear horizontal (SH) wave propagation characteristics were evaluated as a method for identifying defects in stainless steel, with the potential application of developing technology for inspecting defects during operation of nuclear reactors. Defects were positioned between a transmitter and receiver, and the propagation angle of the ultrasonic wave was varied by changing the transmission frequency. Next, the waveform from a defect was compared to reference waveform data for the case of no defects. The results showed that the differential signal had maximum amplitude at 500 and 700kHz in the case of defects in the front surface, and at 560kHz for defects at the bottom surface. We found that the transmission frequency yielding maximum signal amplitude was equal to the propagation direction of the ultrasonic wave, that is, the frequency determined from the direction angle, acoustic velocity and width of the permanent magnet. Further, from a study of the transmission and received frequencies, we found that in the case where the received frequencies were different from the transmission frequencies, the received frequency varied with the depth of defects.