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

Abstract

Ultrasonic guided waves are widely used in industrial nondestructive testing 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 shear horizontal 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 periodic permanent magnet (PPM) electromagnet acoustic transducer (EMAT) to generate the SH0-wave, and the arrayed PPM EMAT to detect the T(0, 1)-wave are designed and built.