基于导波的圆管横向裂纹检测的数值模拟与试验

Numerical simulation and experiment investigation of circumferential crack detection in pipeline based on guided wave

研究圆管上的超声导波的裂纹几何尺寸与回波反射特征间的映射关系.首先,建立5组周向角度与径向深度的裂纹管道的有限元仿真模型,用脉冲-回波的方法模拟L(0,2)模态波对管道横向裂纹进行检测,提取其裂纹反射系数特征值;其次,搭建导波检测系统,加工3组周向裂纹的圆管试样,分别用单探头与4个探头进行裂纹检测试验.分析表明:试验与仿真分析得到缺陷尺寸对反射系数的影响趋势吻合;能够检测到1m以外的裂纹,轴向定位误差小于10%;裂纹回波的反射系数随着损伤程度的增大而增大.本研究为基于导波对管道横向裂纹的定位与识别提供了参考.

This paper studies the reflection relationship between the size of the crack and the reflection fea- ture of the echo of the ultrasonic guided wave. At first, five groups of the finite-element simulation models of cracks with different circumferential sizes and axial depths were developed and the circumferential cracks were detected by modal wave L（0,2） simulated in pulse-echo method, subsequently; the feature value of the crack reflection coefficient was extracted. Secondly, a guided wave detection system was set up. 3 groups of crack models in the numerical simulation were developed; and the detection test of crack models was conducted respectively by a detector or 4 detectors. Analysis indicates, in the experiment, the trend of the reflection coefficient influenced by the crack size is identical with that in simulation analysis. The crack 1 meter and farther from the detector could be detected and the axial location deviation is less than 10%. The reflection coefficient of the echo increased along with the crack level rose. The research results provide a reference to the location and identification of circumferential crack of pipeline based on guided wave.