Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
猿田 晃一; 小林 喬郎*
EUR-26577-EN, p.490 - 496, 2014/07
Fiber Bragg gratings (FBGs) are one of the promising sensor elements for structural health monitoring due to multi-point sensing capability of strain with a high sensitivity and spatial resolution. While current FBG strain sensors based on wavelength domain have been established and found a variety of applications, the number of FBGs in a single sensing arm is in practice limited up to several tens. This number of FBGs is insufficient to develop effective structural health monitoring systems by taking full advantage of multiplex capability of FBG sensors. We report a design and experimental demonstration of FBG strain sensor based on optical-time domain reflectometry (FBG-OTDR). In the presented method strain is measured as a change in the optical power reflected from FBGs, and each FBG signal is separated in time domain. Thus the number of FBGs is not limited by the spectrum range of the light source and the grating bandwidth. The experimental results show that 50 sensing points in a single sensing arm can be measured with an rms error of less than 1 microstrain.
石見 明洋; 小高 英男; 勝山 幸三; 古屋 廣高
no journal, ,
照射済燃料集合体の構造変化を観察するため、X線CT技術を用いた非破壊検査技術を開発した。X線CTシステムでは、燃料集合体から放出される線の影響を低減するために12MVX線パルス発生と検出タイミングをシンクロさせている。本技術を照射済燃料集合体の試験に適用することで、燃料集合体の横断面画像の取得に成功した。この技術は、いくつかの破壊試験の代わりとして適用することが可能であり、照射後試験で発生する放射性廃棄物の低減にも貢献する。