Paper Title
The Application f Guided Wave on Pipe Structure Thickness Detection

Abstract
One of the possibilities for the foundation pile damage of offshore wind turbine is due to seawater corrosion. Therefore, a real time thickness detection is necessary for the wind turbine maintenance. This paper developed a waveguide system to detect the thickness change of the foundation pile. The transducers and angle-variable wedge employed in the system for L(0,2) mode detection were self-made. The group velocity of the echo signal was measured to verify the thickness change. The result show that this system is useful for thickness detection and health monitoring of the pile. Keywords: Waveguide, Offshore wind turbines, Longitudinal wave, group velocity.