Investigation of Strain-Temperature Cross-Sensitivity of FBG Strain Sensors Embedded Onto Different Substrates  

作　　者：Heying QIN Pengfei TANG Jing LEI Hongbin CHEN Boguang LUO 

机构地区：[1]Collaborative Innovation Center for Exploration of Hidden Nonferrous Metal Deposits and Development of New Materials in Guangxi,Guilin University of Technology,Guilin 541004,China [2]Guangxi Engineering Research Center of Intlligent Structural Material,Guilin University of Technology,Guilin 541004,China [3]Guangxi Key Laboratory of Geotechnical Mechanics and Engineering,Guilin University of Technology,Guilin 541004,China

出　　处：《Photonic Sensors》2023年第1期85-101,共17页光子传感器（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52068014);Key Research&Development Projects in the Guangxi Autonomous Region(Grant No.GUIKE AA20302006);Major Construction Program of the Science and Technological Innovation Base in the Guangxi Autonomous Region(Grant No.2018-242-G02).

摘　　要：The strain-temperature cross-sensitivity problem easily occurs in the engineering strain monitoring of the self-sensing embedded with fiber Bragg grating(FBG)sensors.In this work,a theoretical investigation of the strain-temperature cross-sensitivity has been performed using the temperature reference grating method.To experimentally observe and theoretically verify the problem,the substrate materials,the preloading technique,and the FBG initial central wavelength were taken as main parameters.And a series of sensitivity coefficients calibration tests and temperature compensation tests have been designed and carried out.It was found that when the FBG sensors were embedded on different substrates,their coefficients of the temperature sensitivity were significantly changed.Besides,the larger the coefficients of thermal expansion(CTE)of substrates were,the higher the temperature sensitivity coefficients would be.On the other hand,the effect of the preloading technique and FBG initial wavelength was negligible on both the strain monitoring and temperature compensation.In the case of similar substrates,we did not observe any difference between temperature sensitivity coefficients of the temperature compensation FBG with one free end or two free ends.The curves of the force along with temperature were almost overlapped with minor differences(less than 1%)gained by FBG sensors and pressure sensors,which verified the accuracy of the temperature compensation method.We suggest that this work can provide efficient solutions to the strain-temperature cross-sensitivity for engineering strain monitoring with the self-sensing element embedded with FBG sensors.

关 键 词：FBG sensor self-sensing element embedded FBG sensor cross sensitivity of strain and temperature temperature compensation 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]