Researches of the Differential Fiber Bragg Grating Seepage Pressure Sensor

Abstract:

Seepage pressure is the pressure of pore fluid inside soil, which directly influences the stability state of engineering structure. A differential fiber Bragg grating seepage pressure sensor is developed, in which two fiber Bragg gratings are respectively pasted on the top and bottom surfaces of the uniform intensity cantilever. Acted as the seepage pressure measurement cavity, the free end of metal bellows is connected to the cantilever girder free end. Under the pressure of pore fluid function, the engender axial displacement of metal bellows is converted to the deflection change of cantilever girder free end, which generates the wavelength shifts of two pasted fiber Bragg gratings. The experiment results of pressure loading and unloading show that the sensitivity of the sensor is 1.96 nm/ MPa, the repeatability error is 2.27% FS, and the nonlinear error is 1.7% FS.

• Periodical: Applied Mechanics and Materials (Volume 364)
• Pages: 223-227
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.364.223
• Online since: August 2013
• Authors: Bi He, De Li Li, Chuan Li, Ying Na Li, Ya Ping Zhou
• Keywords: Fiber Bragg Grating (FBG), Metal Bellows, Seepage Pressure, Strain, Uniform Intensity Cantilever, Wavelength Shift

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