半导体光电, 2018, 39 (3): 394, 网络出版: 2018-06-29
基于光纤光栅的等截面悬臂梁固有频率研究
Study on Natural Frequencies of Cantilever Beam Based on Fiber Grating
等截面悬臂梁 固有频率 光栅 阶跃信号 模态分析 uniform cantilever beam natural frequency optical grating step signal modal analysis
摘要
介绍了一种基于光纤传感技术的等截面悬臂梁固有频率的测量方法, 并采用理论计算和软件仿真对其进行了验证。首先, 理论推导了粘贴于悬臂梁表面的光栅中心波长与其所在位置处挠度的关系; 然后, 根据分析结果, 搭建了实验测量系统, 该实验采用高温火焰烧断连接线的方法产生一个初始的阶跃信号, 测量结果为20.093Hz; 接着, 采用里兹法对梁固有频率进行理论计算, 结果为20.311Hz; 最后, 利用ANSYS软件对悬臂梁进行模态分析, 得到梁的一阶模态为20.44Hz。实验测量结果与理论计算、有限元仿真结果十分接近, 证明了该方法是正确、可行的, 为悬臂梁固有频率的获取提供了新思路。
Abstract
Introduced is a method based on optical fiber sensing technology for measuring the natural frequency of uniform cantilever beam, and it was verified by theoretical calculation and software simulation. Firstly, the relationship between the central wavelength of the fiber grating and the deflection at the location of the cantilever was deduced. Secondly, according to the analysis of the relationship between the central wavelength of grating and the deflection of cantilever beam, an experimental measurement system was built, and an initial step signal of 20.093Hz was generated by firing the connected line in the experiment. Thirdly, the natural frequency of the beam was calculated as 20.311Hz by Ritz method. Finally, the modal analysis of the beam was carried out by using ANSYS software, and the result is 20.44Hz. The experimental result is very close to that of the theoretical calculation and the finite element simulation. It is proved that the experimental method is correct and feasible, providing a new, simple and feasible method for obtaining the natural frequency of the cantilever beam.
朱晓辉, 俞梅. 基于光纤光栅的等截面悬臂梁固有频率研究[J]. 半导体光电, 2018, 39(3): 394. ZHU Xiaohui, YU Mei. Study on Natural Frequencies of Cantilever Beam Based on Fiber Grating[J]. Semiconductor Optoelectronics, 2018, 39(3): 394.