Based On BOTDR And Fiber Grating Of The Monitoring System Structure Application Study

The main characteristics of Brillouin optical time domain optical fiber monitoring technology isa distributed, high precision, anti electromagnetic interference, set transmission and sensing andintegration.Therefore，it has the warning function good for cable fault, geological disaster preventionand control.It has attracted much attention from all developed countries, research institutions, and itsdevelopment prospects are very good.According to the unique advantages of light weight, high spatial resolution, easy to form thequasi-distributed network and so on, Fiber Grating has made the structural health monitoringtechnology based on fiber sensing into a new hot spot focused by the current domestic andinternstional researchers, with the great application prospect in the field of aviation structure healthmonitoring.Then, this dissertation aims to research on the application of distributed optical fiber and fibergrating in optical cable and aviation health monitoring, including the optical fiber Brillouin frequencyshift effects of different core parameters and modulation layer, the fracture monitoring for CFRPcomposite structure, lightning high voltage impact test. All these work provides theoretical andpractical preparation for promoting the availability of the structure health monitoring technology.The main achievements are described as follows:(1) An optical fiber Brillouin frequency shift response characteristics modulation scheme basedon fiber optimized attribute core material with modulation layer structure of package design. Then therelation model of optical fiber Brillouin frequency shift response is researched, access to the opticalfiber Brillouin frequency shift sensitivity modulation structure properties of different sensing packagemodel effect, construction of the built-in modulation layer distributed fiber is tested with temperaturesensitization and strain desensitization. In order to achieve the purpose of temperature and strainmonitoring of optical fiber.(2) The whole structure of composite is studied with optical fiber Bragg grating sensor. Thischapter utilizes the properties of FBG strain for T type integral structure of drawing under clampedand hinged clamp mode is not continuous and continuous signal monitoring. The optical fiber sensingsystem of fiber grating center wavelength of the instantaneous response signal change analysis,monitoring implementation of the internal structure of CFRP fracture. (3) To build a real-time monitoring system using fiber Bragg grating sensor network. Researchon typical damage forms of lightning test carbon fiber composite laminates. The composite laminatesimpact load position and mechanical characteristics are analyzed, the relationship between the sensorsmonitoring signal and arrangement, arrangement angle, position.