基于异构光栅的钢轨附加力监测技术研究

发布时间：2018-05-21 04:22

  本文选题：光栅传感 + 现场工况　； 参考：《西南交通大学》2017年硕士论文

【摘要】：无缝钢轨以其独有的优势得到世界各国铁路部门的青睐,同时无缝线路的健康状态也成为人们研究的焦点。光纤光栅传感技术拥有高测量精度、体积小等诸多优点正成为轨道安全监测的新型应用。通过光纤光栅反射回来的波长信息进行相应数据处理可以推算出轨道的运行状态,对线路的运营安全做出指导性参考。在本文中,光纤布拉格光栅(Fiber Bragg Grating)传感技术将被应用于轨道健康监测系统中,针对不同无缝线路工况推导出不同的光纤光栅传感特性,继而结合现场不同工况下光纤光栅传感特性提出了一套铁路附加力测量的方案。本文首先对无缝线路研究背景和目的做了简介,并将国内外钢轨纵向附加力研究方法做了总结,针对附加力测量中存在的问题引出本文主要工作和结构安排。之后介绍光纤光栅温度及应变传感特性,同时对光纤光栅在应用中常见的温度和应变同时交叉影响问题做了解决方法归纳,最后为了能将光纤光栅应用于恶劣测量环境中,对光纤光栅封装工艺做了部分研究。其次模拟铁路现场工况,即钢轨竖向及轴向分别处于自由以及受约束的受力状态,探究在这两种条件下的光纤光栅传感原理并加以实验验证,实验结果表明在轨温变化60℃范围内,FBG_1与FBG_2传感特性的理论推导值与实际测量之间的误差分别为1.6%和3.2%。通过对不同约束条件光纤光栅传感特性的验证不仅可标定出光纤光栅的应变以及温度灵敏度系数,同时可以为无缝线路纵向力有效测量提供更多的理论依据。最后介绍铁路无缝线路钢轨固定区附加力测量困难的原因,针对此困难提出一种用于测量附加力的新型光纤光栅结构一异构光纤光栅传感器,并对异构光纤光栅传感器测量钢轨附加力做了原理推导,通过实验验证异构光栅相对波长差与纵向附加力具有高于0.999的线性度,且通过异构光栅测量得纵向附加力与理论值的误差在5%以内。异构光栅不仅可以解决自身温度补偿问题,同时温度变化导致的无缝线路应变监测困难也可得到有效解决,之后结合之前设计的封装工艺来进行异构光栅封装保护,并对封装后的异构光栅进行附加力的测量,其中使用封装后异构光栅传感器测量附加力精度可达92.5%。
[Abstract]:Because of its unique advantages, the seamless rail has been favored by the railway departments all over the world, and the health status of the seamless rail has also become the focus of research. Fiber Bragg grating (FBG) sensing technology has many advantages, such as high measurement precision and small size, which is becoming a new application of track safety monitoring. Through the corresponding data processing of the wavelength information reflected from the fiber grating, the operating state of the track can be calculated, and the guiding reference for the operation safety of the line can be made. In this paper, fiber Bragg grating sensing technology will be applied to track health monitoring system. Then, according to the sensing characteristics of fiber Bragg grating (FBG) in different working conditions, a set of railway additional force measurement scheme is proposed. In this paper, the background and purpose of the research on CWR are introduced, and the research methods of longitudinal additional force of rail are summarized, and the main work and structure arrangement of this paper are brought forward in view of the problems existing in the measurement of additional force. Then, the temperature and strain sensing characteristics of fiber grating are introduced, and the common cross-effects of temperature and strain in the application of fiber grating are summarized. Finally, in order to be able to apply fiber Bragg grating in harsh measurement environment, The packaging technology of fiber grating is studied in part. Secondly, the paper simulates the working condition of railway field, that is, the vertical and axial direction of rail are in the free and constrained state respectively. The principle of fiber Bragg grating sensing under these two conditions is explored and verified by experiments. The experimental results show that the errors between the theoretical derivation of the sensing characteristics of FBG-1 and FBG_2 and the actual measurements are 1.6% and 3.2% respectively in the range of 60 鈩，

本文编号：1917731