Study On Mechanical Vibration And Experiment Based On Fiber Bragg Grating Sensors

Mechanical vibration is strongly entrenched in various problems of mechanical equipments, thus measurements of vibration play a significant role in the analysis, control and optimization of different kinds of mechanical vibration problems. By measuring vibration, not only can we enhance normal mechanical operation, optimize the parameters, increase the service life and improve survival rate, but also can we make some improvement in people's living environment. Giving the problems of long stability, distribution detection and durability in traditional electrical measuring sensor, especially of the unavoidable security risks when inputting electrical signals to dangerous areas, scholars from home and abroad have been devoting themselves to finding out a fungible method of measuring mechanical vibration. The author of the thesis holds that optical fiber sensing technology makes up the deficiency of traditional electrical sensor system, in particular, it is essentially secure, which an advantage for solving security parameter detection problems in complex environments.The author of this paper takes the application of fiber granting sensing technology in machinery equipment as an entry point; by combining the characteristics of fiber grating sensor, the author proposes the method of detecting torsional vibration via fiber Bragg grating. In the paper, the author firstly analyzes the characteristics of fiber gratin sensor in vibration measurement; secondly, on the basis of fiber grating sensor, the author manages to detect mechanical vibration via relevant experiments, and preliminary experiments confirmed the feasibility and advantages of this method (non-contact direct measurement). The main contents of the thesis are as follows:(1) The author briefly introduces research status of torsional vibration measurement method, and the development and application of fiber optic sensing technology.(2) The author analyzes the theory of fiber grating sensor, then carried out the dynamic characteristics of fiber grating sensor research, motivated by 10～700Hz cantilever vibration testing to verify the frequency of vibration response of FBG sensors within the frequency range in the 700hz is completely satisfied. (3) By setting up a rotational experimental platform, the author designs an optical signal non-contact transmission set and achieves non-contact signal transmission. Finally, through rotating shaft torsional vibration experiments, the author verifies the feasibility of detecting torsional vibration on the basis of fiber grating sensor.