Bragg光纤光栅传感器内不均匀应力分布的模拟和重构

介绍了对加载随机的不均匀应力的光纤光栅进行反射谱的模拟和应力分布的重构.利用传输矩阵以及改进的矩阵两种方法,很好地实现了加载随机应力的光纤光栅的反射谱模拟.利用去层法实现光纤光栅应力分布重构的两种随机应力分布重构方法.由于光纤光栅的脉冲响应时域信号严格对应于光纤光栅结构的轴向分布,利用这种因果性质,在已知光纤光栅反射谱的情况下,先获得靠近光纤光栅入射端的一小段光纤光栅所受的应力,再通过去层方式,逐步获得整个光纤光栅的应力分布.两种重构方式分别利用了时域脉冲响应信号的时域截断特性和相位特征,准确获得了光纤光栅上所受的不均匀应力分布.这种随机应力分布重构的方法使得光纤光栅可以应用在小构件以及精细结构上应力集中点的非均匀应力测量和分析上.

Simulation and reconstruction for nonuniform strain profile of fiber Bragg grating sensor

The paper describes the reflected spectra simulation and strain profile reconstruction of the fiber Bragg grating(FBG)with an arbitrary nonuniform applied strain.The reflected spectrum is well simulated with propagation matrix and its modified matrix.Two methods based on layer peeling are presented to reconstruct the arbitrary strain profile.Since the time domain pulse response of FBG is strictly determined by corresponding FBG structure,the strain applied on the front of the FBG can be reconstructed with known reflection spectra,and the strain profile is reconstructed with layer peeling.Two methods reconstruct the strain using the FBG time domain pulse response character of partly truncation and phases,respectively.The strain profile reconstruction can be applied on the measuring and analyzing the nonuniform strain profile of fine construct and stress concentration points.