The induced strain of a fiber optic sensor by the host structure and the measurement study

• Main Authors: Chang-Yu Tsai, 蔡昌宇
• Other Authors: Shiuh-Chuan Her
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/85662038639304166348

碩士 === 元智大學 === 機械工程學系 === 91 === By using the fiber optic sensor, structure is able to detect its own strain, stress and temperature, monitoring working status, substaneously increase the structural performance and reliability. In this research, the strain of a fiber optic induced by the host structure is investigated for both the embedded and surface bonded fiber optic sensor. The farfield strain in the host material is transferred to the fiber optic via the adhesive layer and coating. Thus, the strains between the host structure and optic fiber are different, the relationship is derived on the basis of elasticity theory. The effects of fiber optic length, material properties of adhesive and coating, and the thickness of host structure on the induced fiber optic strain are examined by the parametric study. The case of Mach-Zehnder interfermetric fiber optic sensor in measuring strain is explored. Tests are performed with fiber optic bonded on the surface of a specimen, subjected to four-point bending, three-point bending and uniaxial tension test. The experimental results are compared with the theoretical prediction, to evaluate the accuracy of the proposed model in determing the fiber optic strain.