STRAIN AND TEMPERATURE MEASUREMENT IN FIBRE REINFORCED COMPOSITES USING A NOVEL INTEGRATED FIBRE BRAGG GRATING/EXTRINSIC FABRY-PEROT SENSOR

摘要

This paper reports on a novel optical fibre sensor configuration for conducting simultaneous strain and temperature measurements. The sensor consisted of an optical fibre-based extrinsic Fabry-Perot interferometer (EFPI) with an integrated fibre Bragg grating (FBG). The FBG was located within a glass capillary which houses the EFPI sensor and was thus in a strain-free condition. The FBG was primarily sensitive to temperature, whilst the EFPI was sensitive to both strain and temperature. The integrated FBG/EFPI sensor was embedded in a carbon fibre reinforced composite and evaluated. The standard deviation of strain measurement was 36 με in the range 0 to 1200 με and the temperature measurement had a standard deviation of 3.5°C in the range 30°to 70°C. The thermal apparent strain in a cross-ply composite was investigated and was found about 3.5 με/K.