超声导波管道缺陷定位方法研究*

本文提出了一种基于多换能器的超声导波管道缺陷定位方法，利用两个环形换能器阵列分别接收与缺陷相关的反射信号和透射信号，实现管道缺陷轴向及周向定位。首先利用变分模态分解法对信号进行滤波，在滤除噪声的基础上对信号进行小波变换，获得缺陷反射的导波时频信息，根据反射波的渡越时间计算缺陷在管道轴向的位置。在缺陷的周向定位上，提出一种损伤指数迭代方法，根据透过缺陷后导波的损伤指数来计算缺陷的周向位置及周向长度。仿真和实验结果表明，本文所采用的方法能够较为准确的测量出管道上缺陷的位置及周向长度。

Ultrasonic guided waves for defect location in pipeline

This paper proposes a multi-transducer-based ultrasonic guided wave pipeline defect location method, which uses two annular transducer arrays to receive the reflection signal and transmission signal related to the defect, respectively, to realize the axial and circumferential positioning of the pipeline defect. Firstly, the signal is filtered by the variational modal decomposition method, and the wavelet transform is performed on the signal on the basis of filtering the noise, and the time-frequency information of the guided wave reflected by the defect is obtained. Calculate the axial position of the defect on the pipeline according to the transit time of the reflected wave. On the circumferential location of the defect, an iterative method of damage index is proposed, which calculates the circumferential position and circumferential length of the defect according to the damage index of the guided wave after passing through the defect. Simulation and experimental results show that the method used in this paper can accurately measure the location and circumferential length of the defects on the pipeline.