基于超声导波概率成像的管道损伤中心定位研究

Research on the location of pipeline damage center based on the probability imaging of ultrasonic guided wave

为利用超声导波快速检测管道损伤,并对损伤的轴向及周向进行定位,本研究在有预制轴向裂纹的304不锈钢管(外径47.57 mm、壁厚1.64 mm)中进行超声导波检测实验,利用放置虚拟接收传感器获得导波实际直达路径,通过分析损伤前后局部接收的导波信号的相关性得到损伤因子,利用概率成像技术进行轴向裂纹的定位与成像。结果表明:(1)放置虚拟接收传感器可以抑制成像背景,减小过度加权的影响,并扩大检测能力较高的区域。(2)概率成像技术可在无需控制导波模态的情况下实现管道损伤定位,可视化表达损伤中心的位置信息。(3)当布设的传感路径同轴向裂纹成一定角度时可用于管道轴向裂纹的检测。本研究所设传感网络可准确定位1 m检测范围中轴向长度为10 mm以下的损伤。本研究结果可为管道轴向裂纹检测提供理论参考。

The experiment of ultrasonic guided wave detection is carried out in 304 stainless steel pipe with prefabricated axial crack(outer diameter of 47.57 mm,wall thickness of 1.64 mm)in order to detect the pipeline damage by ultrasonic guided wave and locate its axial and circumferential directions.The actual direct path of the guided wave is obtained by placing virtual receiving sensor.The damage factor is obtained by analyzing the correlation of locally received guided wave signals before and after the damage.The probability imaging technology is used to locate and image the axial crack.The experimental results show that:(1)Placing a virtual receiving sensor can suppress the imaging background,reduce the excessive weighting and expand the area with high detection ability accordingly.(2)Probability imaging technology can locate the pipeline damage and visualize the location information of the damage center without controlling the guided wave mode.(3)The axial crack of pipeline can be detected when the arranged sensing path is coaxial to the crack at a certain angle.The sensor network arranged in this study can accurately locate the damage with an axial length of less than 10 mm in the detection range of 1m.The results can provide a theoretical reference for the detection of axial cracks in pipelines.