Researches On Fiber Grating Strain Sensor Technology For Large Structures

In recent years, with the rapid development of the domestic economy, to meet the need for industry and infrastructure construction, production scale is becoming lager and more efficient day by day and large structure are playing a more and more important role in the process of social production. At the same time, due to the frequent accident caused by the overload of large structure, the social economy suffers great loss and the life safety of the masses is under great hidden danger. Therefore, it is very important to monitor the health of large structure and ensure its safe operation, which puts forward higher requirements for sensing technology. Fiber Bragg grating sensor has been concerned widely in respect of large structure health monitoring due to various advantages such as its properties of lightweight, anti-corrosion, anti-electromagnetic interference and easy to form distributed sensing networks. Our research group has deeply studied the Fiber Bragg grating strain sensor technology. On this basis, Fiber Bragg grating strain sensor technology for large structural health monitoring was studied. What’s more, we also explored packaging methods to separate the cross-sensitivity of temperature and strain. The specific research work of this paper is summarized as follows:Firstly, the current research status of Fiber Bragg grating was introduced; the sensing characteristics of the fiber Bragg grating strain sensor and its application status in the field of large structure health monitoring were illuminated.Secondly, the principle of Fiber Bragg grating strain sensing and a few common packaging were studied. Based on the principle of fiber Bragg grating strain sensing, two packaging schemes of fiber Bragg grating strain sensor were carried out, and the sensing properties were tested.Thirdly, the technology of the separating cross-sensitivity of strain and temperature was investigated systematically, a few common separating schemes were discussed. One kind of Fiber Bragg grating sensor was designed to measure the temperature and strain simultaneously and a testing system was set up to test its strain sensing properties.Finally, the large strain measurement in large structure health monitoring was studied and one kind of large strain sensor was fabricated which could also realize temperature compensation functions. The strain sensing characteristic testing system was set up, and a few sensing experiments were done to study the strain sensing properties.