Characteristics of SH0-wave Converted to T(0, 1)-wave Based on a T-shaped Plate Wrapped Around a Pipe.

Ultrasonic guided waves are widely used in industrial NDT for pipes and plates, where pipe-waves and plate-waves exhibit similar behaviors for some specific modes. This paper investigates the characteristics of an SH0 mode plate-wave converted to a T(0, 1) mode pipe-wave based on their similar dispersion and wave structure properties. First, the analytical solution is initially proposed to analyze the characteristics of the SH0-wave propagation in a model of arrayed plates coupled to a pipe. The dispersion curves of the SH-waves are established in a bounded double layer plate in which the effect of the material and the effect of the thickness ratio of the layers are both considered. An equivalent model of a T-shaped plate wrapped around a pipe is then presented and the numerical simulation of the SH0-wave propagation in the T-shaped plate is studied. Finally, the validity of the model is verified by experiments in which the PPM EMAT to generate the SH0-wave and the arrayed PPM EMAT to detect the T(0, 1)-wave are designed and built.