The Use of OLCR Technology for Fiber Bragg grating sensing of distributed non-uniform strains[J]. Optics and precision engineering, 2010, 18(1): 1-8.DOI:
The reflectivity spectrum of a fiber Bragg grating (FBG) is out of shape under non-uniform strain loading
so the strain can not be deduced from the shift of Bragg wavelength. The optical low coherence reflectometry (OLCR) technology is supposed to be a reliable method for measuring the non-uniform strain of FBGs. Based on a Michelson interferometer
OLCR system is set to interrogate the time domain pulse response of FBG structure
from which the frequency domain reflection response of FBG is converted by Fourier transform. Then the spatial response of FBG
relevant to Bragg wavelength is reconstructed from lay peeling technology. Thus
the non-uniform strain distribution is calculated from the sensing model of FBG. With an effective OLCR system
the OLCR technology is illustrated in detail. An experiment of composite delamination in modeⅠis conducted
and the non-uniform strain distribution is botained with reliability. The OLCR system demostrates an excellent performance in demodulating the FBG non-uniform strain sensing