Study And Application Of Fiber Bragg Gratings Strain Sensor

One of the most important physical properties of materials & structure is strain, which is also an essential parameter for measurement and monitoring. Present technologies have some deficiencies that can't be put to long-term efficient measurement. This thesis describes the research and development of a fiber grating strain sensor and long-term monitoring system to meet the needs of national construction, and the sensing and monitoring system will be the first to be mass applied domestically in long-term safety monitoring of bridge, architecture and other critical engineering structures.This thesis, on the basis of theoretical research of fiber Bragg gratings, focuses on the systematic analysis of the strain and temperature sensing properties of fiber gratings, proves the priority of the application of fiber gratings to strain measurement. According to the systematic research on the compatibility, sensing properties, temperature compensation in strain measurement and encapsulation, the scheme of fiber Bragg grating strain sensor is put forward and three new types of fiber optic Bragg grating strain sensors are developed and tested. During the application of the sensors in bridges, architectures and other critical engineering structures, we make systematic analysis on the key problems such as the devise of FBG long-term strain monitoring system, basic structure, optimization of sensing network, temperature compensation and temperature detection of the system, sensor distribution, and protecting crafts. Results shows that the scheme of FBG strain sensor in this paper is feasible, several kinds of strain sensors are developed with good anti-disturbance ability, high sensitivity and long durability, which can meet the needs of long-term monitoring of critical engineering structure strain conditions and has a wide application prospects.