利用光纤光栅实现力学量二维实时感测的研究

Real Time Sensing and Measurement for Two Dimensional Dynamics Quantities Using Fiber Grating

将一根光纤上写入两个不同波长的布拉格光栅 ,沿矩形悬臂梁的中性面与表面的交线粘贴于靠近固定端两个相邻侧面 ,利用光纤光栅波长绝对编码的特性 ,实现了应力 (或应变 )与位移的二维实时传感测量。理论分析和实验结果证明 ,通过监测粘贴于梁上的两个光纤光栅波长变化的大小和指向 ,能够实时感测应力、位移等力学量的大小和方向。在与梁轴垂直的方向上 ,获得应力实验灵敏度分别为 5 .32nm/N和 3.2 1nm/N ,位移实验灵敏度分别为 0 .30nm/mm和 0 .4 8nm/mm。

The two fiber gratings with two different wavelengths in a single mode fiber are bonded to the two neighboring side faces near the fixed end along the axial direction of a cantilever beam. Using the characteristics of fiber grating encoding, we have realized the measurement of the two dimensions for the stress or the displacement. The theoretical analyses and the experimental results indicate that the magnitudes and the directions of the stress, displacement and other mechanical quantities can be sensed and measured in real time through monitoring the value and direction of the wavelength shift of the two fiber gratings that are bonded to the near fixed end of the cantilever beam. In the vertical directions of the cantilever beam axis, the experimental sensitivities of the stress are 5.32 nm/N and 3.21 nm/N, the experimental sensitivities of the displacement are 0.30 nm/mm and 0.48 nm/mm, respectively.