Shu Minakuchi1, Tadahito Mizutani1, Haruka Tsukamoto2, Mayuko Nishio2, Yoji Okabe3, Nobuo Takeda1
Structural Durability & Health Monitoring, Vol.4, No.4, pp. 199-220, 2008, DOI:10.3970/sdhm.2008.004.199
Abstract The authors propose a technique to detect centimeter internal damages in large-scale composite structures, using an optical fiber network running throughout the structure. A Brillouin-based distributed strain sensing system with centimeter-order spatial resolution (pre-pump pulse Brillouin optical time domain analysis (PPP-BOTDA)) was utilized to detect residual non-uniform strain in the damaged area. First, Brillouin spectral response depending on the strain profile within the spatial resolution was revealed. The spectral response depending on strain non-uniformity was experimentally quantified with consideration of the general characteristics of the Brillouin gain spectrum. Then, the damage detection procedure was proposed, More >