• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Multi-parameter measurement in composite structures using embedded fiber optic sensors.
【24h】

Multi-parameter measurement in composite structures using embedded fiber optic sensors.

机译：使用嵌入式光纤传感器的复合结构中的多参数测量。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This dissertation attempts to extend the state-of-the-art of multi-parameter fiber optic sensors for structurally embedded applications. Three main purposes have been addressed in this dissertation for the applications of fiber optic sensors embedded in composite structures: (1) simultaneously measuring both strain and temperature, (2) simultaneously measuring two strain components, and (3) build the foundation for simultaneously measuring four components of the complete strain state.; First of all, a dual-parameter hybrid sensor made by cascading an in-line fiber etalon and an in-fiber Bragg grating to simultaneously measure axial strain and temperature is presented. This sensor system is analyzed in great details including the optical approach, the micromechanics of the sensor embedded in the composite, and the numerical stability. The experimental results demonstrating the functionality of the dual-parameter sensor by bonding it to the surface of an aluminum cantilever beam and embedding it in a graphite/epoxy composite cantilever beam are given.; Secondly, the extension of the sensor system described above is made to simultaneously measure axial strain and transverse strain in the composite cantilever beam. The requisite micromechanics is developed for the two-strain sensor using concentric cylinder models. The internal axial and transverse strains are measured with the fiber optic two-strain sensor and two resistance strain gages mounted on the surface of the beam. They show very consistent results. The two-strain sensor results are promising, and suggest that it might be possible to develop a multi-axis strain sensor.; Finally, a single micro-optical fiber sensor capable of simultaneously measuring four key elements of the complete strain state at one point in composite material is proposed. The objective of this part is to obtain four strain components in a composite host material (far field strains) using the measured strains from the optical fiber sensor that is embedded in the composite material. The measured strains are then translated into strains in the composite material using approximate transformation matrices and a micromechanical finite element analysis for the sensor and the host material. The fiber transducer is based on cascading four micro Fabry-Perot cavities fabricated from three very different types of optical fibers. These types of fiber are selected because each has a completely different optical response to applied strain, therefore enabling four independent optical measurements to be used to solve for the three normal strains and one in-plane shear strain. The development of the sensor configuration design and micromechanics analysis has been discussed. The sensor design includes designing new type of optical fiber, fabricating in-line micro-attenuators, and embedding the side-hole fibers in the composite at desired orientation. Finite element model was used to design side-hole fiber for maximized sensitivity to transverse strains. Two-dimensional closed form analysis has been used to establish the transformation between fiber sensors and composite host strain state. Then, four linear equations are used to express the desired strains in the host composite in terms of the measured optical phase changes in the multi-strain sensor.
机译：本文试图扩展结构嵌入式应用中的多参数光纤传感器的最新技术水平。本文针对复合结构中嵌入的光纤传感器的应用提出了三个主要目的：（1）同时测量应变和温度，（2）同时测量两个应变分量，（3）为同时测量奠定基础完全应变状态的四个组成部分；首先，提出了一种双参数混合传感器，该传感器由串联的光纤标准具和光纤的布拉格光栅级联而成，以同时测量轴向应变和温度。对该传感器系统进行了详细分析，包括光学方法，嵌入复合材料中的传感器的微力学以及数值稳定性。给出了通过将双参数传感器粘结到铝悬臂梁的表面并将其嵌入石墨/环氧树脂复合悬臂梁中来演示双参数传感器的功能的实验结果。其次，上述传感器系统的扩展是为了同时测量复合悬臂梁中的轴向应变和横向应变。使用同心圆柱模型为双应变传感器开发了必要的微力学。内部的轴向和横向应变是通过光纤两应变传感器和安装在光束表面的两个电阻应变计测量的。它们显示出非常一致的结果。两应变传感器的结果是有希望的，并表明开发多轴应变传感器是可能的。最后，提出了一种能够同时测量复合材料中某一点处的完整应变状态的四个关键元素的单个微光纤传感器。该部分的目的是使用嵌入在复合材料中的光纤传感器测得的应变来获得复合主体材料中的四个应变分量（远场应变）。然后，使用近似转换矩阵以及传感器和主体材料的微机械有限元分析，将测得的应变转换为复合材料中的应变。光纤传感器基于级联的四个微型Fabry-Perot腔，该腔由三种非常不同类型的光纤制成。选择这些类型的光纤是因为每种光纤对施加的应变具有完全不同的光学响应，因此可以使用四个独立的光学测量来解决三个法向应变和一个面内剪切应变。讨论了传感器配置设计和微力学分析的发展。传感器设计包括设计新型光纤，制造在线微衰减器，以及将侧孔光纤以所需的方向嵌入复合材料中。有限元模型用于设计侧孔光纤，以最大程度地提高对横向应变的敏感性。二维封闭形式分析已用于建立光纤传感器与复合主体应变状态之间的转换。然后，根据多应变传感器中测得的光学相位变化，使用四个线性方程式表示主体复合材料中的所需应变。

著录项

  • 作者

    Jin, Xiaodan.;

  • 作者单位

    University of Maryland College Park.;

  • 授予单位 University of Maryland College Park.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2000
  • 页码 132 p.
  • 总页数 132
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 机械、仪表工业;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号