Structural Monitoring of a Maglev Guideway with Wavelength Division Multiplexed FBG Sensors

초록

In the structural monitoring of Maglev guideways, electromagnetic interference (EMI) can be a significant problem as the Maglev train is powered by high-voltage electric feeding systems. Recently, researchers have successfully applied fiber optic sensors to modern rail-way structures mainly due to the EMI-immunity. This study presents an effective methodology on integrated monitoring system for a maglev guideway using wavelength division multiplexing (WDM)-based fiber Bragg grating (FBG) sensors. The physical quantities such as stains, curvatures, and vertical deflections are measured in the field test. The strains are directly measured from multiplexed FBG sensors at various locations of the test bridge followed by curvature calculations based on the plane section assumption. Vertical deflections are then estimated using the Bernoulli beam theory and regression analysis. Frequency contents obtained from the proposed method are compared with those from a conventional accelerometer. Verification tests were conducted on the newly-developed Korean Maglev test track at different speeds ranging from 10km/h to 50km/h.