The effect of defect depth on reflection coefficient of ultrasonic guided waves in steel pipes

Through the analysis of dispersion equation and curves of ultrasonic guided waves in the steel pipes, L (0,2) and T (0,1) mode are applied to the defect detection field. The finite element method is used to analysis the propagation and reflection process of L (0,2) and T (0,1) mode guided waves in the steel pipes with depth varying middle defects, and the conclusion that the relationship between the depth range of the defect and the reflection coefficient of guided waves is linear in steel pipes is summed up. Finally, the conclusion is verified by field test analysis.