Analytical Solution to the Characteristics of S0-wave Converted to L(0,2)-wave Based on a Plate Array Coupled to a Pipe

Ultrasonic guided waves have been widely used in the industrial nondestructive testing of pipes and plates, where the pipe-waves and plate-waves show similar behaviors in some certain modes. In this paper, the characteristics of an S0 mode plate-wave converted to an L(0,2) mode pipe-wave was investigated due to their similar dispersion and wave structure properties. The assumption was initially proposed that the L(0,2) mode pipe-wave could be converted from the corresponding S0 mode plate-wave based on a plate wrapped around a pipe. The equivalent model of a plate array coupled to a pipe was then presented in which the analytical solution to the propagation characteristics of the S0-wave was investigated. Based on the dispersion curve, the effects of the material and the thickness ratio were both studied, which indicated that the L(0,2)-wave can be successfully converted when the similar material and the low thickness ratio are selected.