Finite Element Simulation Study on Detection of Thick-walled Pipes' Defect with Circumferential SH Guided Waves

In this paper, based on finite element simulation software the thick-walled pipes' detection model by using circumferential SH0 mode guided waves was established; the wave structure and the group velocity of the mode guided waves were analyzed; the detection of different wall thickness defects was carried using the mode guided waves. The results show that the wave structure curve of simulation was consistent with theoretical analysis, while the difference of ultrasonic wave propagation velocity and the group velocity of circumferential SH0 mode guided waves at 60 kHz in theoretical dispersion curve was small. These have verified effectiveness of the finite element model. The simulated detection results of the different wall thickness defects show that the detection sensitivity in external wall defect was highest and lower in the middle thick wall defect, while the defect located in the internal wall was difficult to detect.