The Influence Of The Buried Depth On The Monitoring Of FBG Sensor

With the rapid development of road construction, the fiber grating sensing technology are deeply researched in road engineering, due to its excellent performance. But as the result of the complexity, extensive, and other factors of road engineering construction, the practical application of fiber grating technology in road engineering is very little at present. In this Paper, related experimental researches has been done in view of the influence of the buried depth did on fiber Bragg grating sensor on sensor.F-type sensor and P-type sensor was designed by using steel and the polypropylene material. First of all, the calibration test was done by stretching the sensor, then two kinds of static load test was done which is the buried depth of the round load static square and square load test, at last the dynamic load depth test. Analysised the effort of Package kind, testing method, and buried depth on the sensitivity of the sensor load monitoring.The tensile tests of two kinds of sensors showed that the encapsulation process are feasible and effective.Two kinds of Package have different sensitizing effect on the fiber Bragg grating sensor, showed that the two sensor can be applied to different monitoring environment.Considering the original differences of sensor itself,the result of the calibration test was used to eliminate the differences, obtains the change law of sensitivity coefficient of the sensor with buried depth, found that different static load test get the different change regularity. It shows that test method has a significant im Pact on the sensor sensitivity and the regularity between the buried depth and the sensor sensitivity.The dynamic buried depth load test found,that square static calibration test results can be used to calculate the rut instrument dynamic load, but the circular static load calibration test cannot. The test comes to a conclusion that static load test calibration method has a significant influence on the verification result of dynamic load test The response of the sensor has a certain deviation even if the static load was equal to the dynamic load.The thesis put forward that the load difference coefficient can be used to correct the deviation and studied the relationship between the load difference coefficient and the sensor embedded depth, got the formula of the load difference coefficient and the buried depth, Established the calculation formula of measured load of the wheel load.