應用光纖感測器量測敲擊位置與強度

Application of FBG sensors on measuring impact location and intensity

何孟翰(Meng-Han He)

指導教授 ： 何旭川

元智大學/工程學院/機械工程學系/碩士(2013年)

https://doi.org/10.6838/YZU.2013.00341

摘要

光纖光柵承受機械應變所產生之反射光波長偏移，可用於量測結構應力、應變、位移、振動與壓力等物理量。本文以光纖光柵結合光濾波器與光偵測器，將短週期光纖光柵受到衝擊時所造成之反射光波長偏移轉換為光強度電壓變化，藉由量測光柵反射光強度電壓之變化，評估衝擊點所在位置與衝擊力大小。選用之試片為鋁板，並於鋁板中心位置沿0°方向、45°方向與135°方向，各黏貼一條光纖光柵，再以實驗方式求得這三條光柵反射光強度電壓變化與敲擊位置及敲擊力之關係式。最後以隨機方式敲擊鋁板，將量測所得光柵反射光強度電壓變化，代入實驗求得之數學關係式，計算敲擊力與位置，並與實際值比較，兩者相當吻合平均誤差約為5%，驗證光纖光柵量測衝擊力與位置之準確性與可行性。

關鍵字

光纖光柵 ； 光濾波器 ； 光強度 ； 敲擊位置 ； 敲擊力

並列摘要

The shift of Bragg wavelength induced by the mechanical strain can be used to detect many physical quantities such as stress, strain, displacement, vibration and pressures etc. In this work, fiber Bragg grating (FBG) sensors are employed to detect the impact force and location. Fiber Bragg grating is incorporated with optical filter and photo detector so that the shift of Bragg wavelength due to the impact can be converted to the change of light intensity and detected by a photo detector. The test specimen is an aluminum plate. Three fiber Bragg gratings are surface bonded in the central region of the aluminum plate, aligned along the , and , respectively. The mathematical relationships between the light intensity and the impact force and location for each fiber Bragg grating were established basing on a series of experimental tests. Several random impact tests were conducted to verify the proposed model. The light intensities of these three fiber Bragg gratings recorded by the photo detectors were substituted into the mathematical relationships to evaluate the impact force and location. Experimental test results show that the error of impact force and location measured by the fiber Bragg grating sensors is about 5 %. This demonstrates the feasibility of detecting the impact source using the fiber Bragg grating sensors.

並列關鍵字

Fiber Bragg grating ； optical filter ； light intensity ； impact location ； impact force

參考文獻

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[18] 謝文斌，”結合光纖光柵與Mach-Zehnder光干涉量測結構振動”，元智大學機械工程研究所碩士論文 (2007)

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