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论文类型：期刊论文

发表时间：2010-06-01

发表刊物：MEASUREMENT SCIENCE AND TECHNOLOGY

收录刊物：SCIE、EI、Scopus

卷号：21

期号：6

ISSN号：0957-0233

关键字：embedded fiber optic sensor; long gauge; coefficient of thermal expansion; strain-optic effect; thermo-optic effect

摘要：A novel methodology for the determination of the coefficient of thermal expansion (CTE) is proposed by using long-gauge fiber optic sensors. Current approaches either neglect the shear-lag effects or do not compensate for the thermo-optic effects in optical fibers leading to precision errors. The embedded long-gauge sensor measures not only the thermo-optic effect due to temperature fluctuations, but also the strain-optic effect created by thermal stresses. However, it is difficult to directly separate these two effects in the measurements. Given that only the strain-optic effect correlates to the CTE of a host material, it is necessary to compensate for the thermo-optic effect. An additional error is attributed to the fact that the shear-lag effect is ignored, i.e. assumption is made that the strain distribution in the optical fiber is the same as that in the host material. This study reports on the development of a methodology for the computation of the coefficient of thermal expansion in structural materials using long-gauge fiber optic sensors. The proposed formulations account for both the shear-lag and thermo-optic effects.