FBG Used In The Study Of Carbon Fiber Reinforced Concrete Structure Health Monitoring Reliability

In this thesis, the background of reinforced concrete monitoring, the health monitoringof fiber Prague grating sensors in concrete application. The sensing characteristics of FBGfrom the point of view of theory, research on FBG sensor characteristics of stress, strain andtemperature sensing, method of temperature compensation scheme, and the strainmeasurement and its application in carbon fiber reinforced concrete. This paper studies fromthe following two aspects:(1) Lists the research background, the background is mainly the development ofreinforced concrete, research status of carbon fiber at home and abroad, the fiber gratinghistory, characteristics aspects. Focus on the characteristics of fiber gratings, starting from thefiber Bragg grating principle, analysis of the FBG strain and temperature sensing andcharacteristics, and the influence of FBG center wavelength change of the sensor sensitivity,the FBG strain and temperature cross sensitivity, temperature compensation principle isdeduced. In the uniform axial force is obtained compared with center wavelength and thelateral stress the role of drift, found FBG on the axial stress is more sensitive than thetransverse stress, so the study usually only consider the function of axial stress.(2) For structural health monitoring in civil engineering demand, this paper first from3the experimental angle produced100×100of carbon fiber reinforced concrete block. Usingthe measured strain electrical measurement method, to calculate the detection of elasticmodulus. Secondly, making the length of1200,200of the diameter of reinforcing cage,embedded Fiber Bragg Grating Sensor and good resistance strain gauge placed in the middlepart of reinforced cage, and modulation of carbon fiber reinforced concrete pouring formingcylindrical pile. Maintenance period of one month to do after the bending test, the healthmonitoring of fiber Bragg grating sensor, and the temperature compensation. Data show thatconsistent with the expected, proved that the embedded Fiber Bragg Grating Sensor is idealsensing element, carbon fiber reinforced concrete structure of internal strain measurement,can satisfy the practical requirements of the health monitoring.