Study On The Distributed Temperature Demodulating System For The Smart Cantilever Beam Using Optical Fiber Bragg Grating

Fiber smart metal structures have attracted more and more attentions in the last two decades. Due to the remarkable properties, such as such as wavelength encoded nature, wavelength-division multiplexing, immunity to electric–magnetic interference,small size and so on. Fiber Bragg grating(FBG), as a special fiber sensor, holds great potential application in smart metal structure. The structurally integrated FBG sensors inside metals or on the surface of metals can monitor the metal structures’ physical parameters which are not accessible by ordinary sensors. In other words, FBG smart metal structure can monitor the structures’ operation and improve the production efficiency.The central wavelength of FBG shifts as the parameter changes. How to accurately detect the reflection wavelength shift and how to design a synchronous measurement with high resolution, simple operation is one of the key technologies of FBG sensor. FBG cantilever beam structure is often used in the field of precision strain measurement. However, the ambient temperature change will cause a certain effect on strain sensing measurement accuracy.According to a FBG smart cantilever beam. Temperature sensing of the FBG smart cantilever beam structure is investigated. A distributed temperature demodulation system using the FBGA module is developed. A temperature monitoring software of the FBG smart cantilever beam based on Lab VIEW is designed.The main listed are as follows:(1) Simple research status of optical fiber Bragg grating sensor are introduced and the principle of FBGA demodulation module. Bare FBG sensing characteristics are analyzed, metallized FBG sensing features, integrated into the metal structure of FBG sensing properties.(2) Six FBG sensors are protected with different metal coatings, such as copper coating by elelctroless plating and nickel coating by electroplating. For the six FBG sensing grating, bath temperature sensing experiment has beencarried out, and the six FBG sensor’s temperature sensing properties and the effect of different coating on their temperature characteristic are analyzed.(3) The six FBG sensor is glued to the surface structure of FBG smart cantilever beam structure, with which a distribute sensing system is developed. And smart cantilever beam temperature sensing properties are analyzed, and comparative analysis of the paste before and after the six FBG temperature sensing properties and the function of the cantilever beam thermal strain of FBG.(4) For the FBG smart cantilever beam, a temperature monitoring software of the FBG smart cantilever beam based on Lab VIEW is designed. The real-time spectrum, data storage and processing functions are developed.