Theoretical and Simulated Analysis of Guided Waves Propagating in Fluid-Filled Pipes

To keep the safety of nuclear power plants, nondestructive evaluation (NDE) of cylindrical pipes, which carry hot water, is an issue of a great interest. Ultrasonic methods using bulk wave are commonly used for NDE of such pipes, however still having problems that the methods consume a long time to inspect large areas. On the other hand, NDE methods using guided wave should overcome this problem because the guided wave has a characteristic of long propagation range. Nevertheless, there have been few investigations to clarify the behavior of the guided wave in the fluid-filled cylindrical pipes. We therefore developed an analytical method to calculate particle displacement, and we compared the dispersion curves, cut-off frequencies, and particle displacements of guided waves propagating in the hollow pipe and the fluid-filled pipe.