Development and application status of T(0,1) modal guided wave detection technology in pipeline

The ultrasonic guided wave detection technology has the advantages of fast detection speed and wide detection range, and so it has been widely used in pipeline defect detection. The torsional mode, as a symmetric mode of ultrasonic guided wave, is characterized by small dispersion, concentrated energy, single signal and easy to analysis. In this paper, the development of torsional modes in recent years is reviewed. Starting from the propagation and detection principles of torsional guided waves in T (0,1) mode, the excitation principles and effects of various excitation probes are compared, and their advantages and disadvantages are analyzed. By analyzing the selection principle of torsional modes and the characteristics of the guided wave propagation in a single pipe, double wall pipe and liquid filled pipe, the effects of excitation frequency, liquid viscosity, liquid density and other factors on the propagation of torsional mode guided wave in the pipeline are summarized. Furthermore, the suitable scope of torsional mode and the suitable signal processing method are defined, which could provide a reference for the development of torsional mode detection technology in the future.