In this paper, a cement-based acoustic emission sensor is embedded in reinforced concrete, and the corrosion damage inside the concrete is activated by swinging ball impact. The changes of low frequency and high frequency acoustic emission signals are captured and analyzed by the sensor, and the concept of low-high-frequency () is proposed. The changes of acoustic emission characteristics during the corrosion of steel bars were studied, and the effects of protective layer thickness and activation site on the ratio of were analyzed. The results show that with the increase of the corrosion degree, the amplitude of the frequency signal in the range of 13 kHz–22 kHz decreases gradually, from 2.59 mV to 1.29 mV. The amplitude of the frequency signal near 170 kHz increases first and then decreases with the increase of corrosion time. The frequency signal near 22 kHz is used as the low frequency signal, the amplitude of the frequency signal near 170 kHz is used as the high frequency signal, and the ratio of the two is used as the low-high-frequency (). The evaluation result of this ratio is consistent with the ultrasound test results. As the sound source continues to move to both ends of the concrete sample, the distance between this sound source and the sensor gradually increases, the low frequency signal decreases significantly, and changes significantly, influenced by the reflection of the boundary.

中文翻译：

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基于嵌入式水泥基声发射传感器的钢筋混凝土腐蚀状态主被动监测


本文将水泥基声发射传感器嵌入钢筋混凝土中，通过摆动球冲击来激活混凝土内部的腐蚀损伤。通过传感器捕获并分析低频和高频声发射信号的变化，提出了低高频（）的概念。研究了钢筋腐蚀过程中声发射特性的变化，分析了保护层厚度和活化部位对钢筋比例的影响。结果表明，随着腐蚀程度的增加，频率信号在13 kHz~22 kHz范围内的幅值逐渐减小，从2.59 mV减小到1.29 mV。随着腐蚀时间的增加，170kHz附近频率信号的幅值先增大后减小。将22kHz附近的频率信号作为低频信号，将170kHz附近的频率信号的幅度作为高频信号，将两者的比值作为低频-高频()。该比值的评价结果​​与超声检测结果一致。随着声源不断向混凝土试件两端移动，该声源与传感器之间的距离逐渐增大，低频信号明显减少，并受边界反射的影响而发生明显变化。