The Research On Fiber Bragg Grating Acceleration Sensor With High Frequency Response

In the fields which large-scale structures exit in, such as aerospace, electro mechanics engineering, oil and so on, there are complex dynamic problems, it is necessary for them to carry out high-quality vibration testing and analysis, in order to ensure operation of engineering structures safy. So,developing a new type of acceleration sensor for vibration monitoring in these fields has great economic significance and social meaning.As the advent of fiber Bragg grating(FBG) in 1978, the researchers began to reseach on FBG sensors. Compared with electrical sensors, the FBG sensors have many advantages such as wide frequency response range, the nature of anti-electricity, the nature of anti-electromagnetic interference and far signal transmission distance. In addition,because the grating grids are inside the fiber,FBG sensors have many advantages which are not possessed by fiber optic sensor of interference type,such as small volume,little weight and simple structure,moreover,they can constitute a network easily,therefore,The FBG sensors won wide attentions after their appearances. After researching for near twenty years, people developed many kinds of sensors,for example, temperature type, stress type, pressure type, vibration type, displacement type, and so on. Some of these sensors(such as temperature type, stress type and pressure type) have developed perfectly and good effects were attained in project application. Although people have done much research on FBG sensors and some pivotal issues such as "wavelength demodulation" and "temperature compensate" were successfully solved, frequency response index can not satisfy to application requirement in electro mechanics field. At present, the structures of most FBG vibration sensors are cantilever style, the response frequencies of these sensors are restricted under several hundred Hertz by their sensitivity.On the base of general design method on acceleration sensor,and combination with fiber grating sensing technology,this paper proposes the general design method of FBG acceleration sensor,and through indepth research, we developed a high frequency response FBG accelerometer. In addtion,we done detailed theoretical analysis on the factors which might affect the performance of FBG acceleration sensor. we also give reasonable solutions. Through optimal design of structure parameters, we design a new type of high-frequency response FBG acceleration sensors, and done some experimental researches on the sensor. There are good results as a high resonance frequency in 3232hz, a measurement range from 0.1g to 4g and a good linear sensitivity of 669mv/g,which shown that experimental results were in accordance with theoretical research.,the performance indexes of the sensor can be further enhanced by optimizing the structure parameters further.This paper developed a kind of high-frequency response FBG acceleration sensor on which some theoretical and experimental reseaches were carried out,the results shown that the design of the FBG acceleration sensor is so successful that it will play a huge economic and social significance.