Vertical Displacement Approximation of Steel Railway Bridges using Multiplexed FBG Sensor Arrays

초록

The multiplexing capability of fiber Bragg grating (FBG) sensors has great potential for providing high performance structural sensing systems. This paper presents an experimental technique to quantify vertical displacement of the bridge using multiplexed FBG sensor arrays. FBG sensors are installed along the length of steel girders by attachment and the strain-induced wavelength shift is measured. Using the geometric relationship and the regression analyses of curvatures, it is possible to extrapolate the vertical displacement curve of the structure. Field tests are conducted to verify the experimental technique under dynamic load conditions including impact load and passing train load. The results show that the proposed instrumentation technique is capable of estimating the vertical displacement of the bridge for various loading conditions.