The Numerical Simulation Research Of Detect Pipeline Corrosion In Ultrasonic Guided Wave

Because of ultrasonic guided wave testing pipeline has many advantages, such as propagation attenuation is small, high sensitivity, single-point excitation can be tested for long distance and the sound field across the boundary layer. It has been a great concern in the field of pipeline non-destructive testing. It is difficult to analyze test results that guided wave has multiple modal, dispersion and modal transformation features. However, Numerical simulation is an important method for understanding guided wave detection mechanism and identifying pipeline defects. This paper main work is as follows:(1) I used finite element analysis method to build f pipeline corrosion ultrasonic testing numerical simulation model based on L (0,2) and T (0,1) mode excitation. Experimental results show, this algorithm can effectively simulation multiple defects pipeline in ultrasonic guided wave testing, chooses the L (0,2) and T (0,1) mode as the excitation modal simulation, and establish the good research platform for the study of mechanism of guided wave inspection and defect recognition algorithm. (2) When ultrasonic guided wave testing multiple defects in pipeline, dispersion,modal transformation and defect echo interference between each other cause defect information misjudgment. This paper researched the relationship between single defect geometry parameters, the axial spacing of row defects and echo, I presented bidirectional excitation ultrasonic guided wave pipeline corrosion defect detection method, which is superimpose forward and reverse direction guided wave excitation test data. Experimental results shows, this method reduce the interaction between defects echo, improve signal to noise ratio, and thus improve the accuracy of positioning defects and the size of defect recognition rate.