...
首页> 外文期刊>Mechanical systems and signal processing >Identification of modal strains using sub-microstrain FBG data and a novel wavelength-shift detection algorithm
【24h】

Identification of modal strains using sub-microstrain FBG data and a novel wavelength-shift detection algorithm

机译:使用亚微应变FBG数据和新型波长偏移检测算法识别模式应变

获取原文
获取原文并翻译 | 示例
           

摘要

The presence of damage in a civil structure alters its stiffness and consequently its modal characteristics. The identification of these changes can provide engineers with useful information about the condition of a structure and constitutes the basic principle of the vibration-based structural health monitoring. While eigenfrequencies and mode shapes are the most commonly monitored modal characteristics, their sensitivity to structural damage may be low relative to their sensitivity to environmental influences. Modal strains or curvatures could offer an attractive alternative but current measurement techniques encounter difficulties in capturing the very small strain (sub-microstrain) levels occurring during ambient, or operational excitation, with sufficient accuracy. This paper investigates the ability to obtain sub-microstrain accuracy with standard fiber-optic Bragg gratings using a novel optical signal processing algorithm that identifies the wavelength shift with high accuracy and precision. The novel technique is validated in an extensive experimental modal analysis test on a steel I-beam which is instrumented with FBG sensors at its top and bottom flange. The raw wavelength FBG data are processed into strain values using both a novel correlation-based processing technique and a conventional peak tracking technique. Subsequently, the strain time series are used for identifying the beam's modal characteristics. Finally, the accuracy of both algorithms in identification of modal characteristics is extensively investigated.
机译:土木结构中损坏的存在会改变其刚度,从而改变其模态特征。这些变化的识别可以为工程师提供有关结构状况的有用信息,并构成基于振动的结构健康状况监视的基本原理。尽管本征频率和模式形状是最常监控的模式特征,但相对于其对环境影响的敏感性,它们对结构破坏的敏感性可能较低。模态应变或曲率可以提供一种有吸引力的替代方法,但是当前的测量技术在捕获具有足够精度的环境或工作激励过程中发生的非常小的应变(亚微应变)水平时遇到了困难。本文研究了使用新颖的光信号处理算法以标准的光纤布拉格光栅获得亚微应变精度的能力,该算法可以高精度和高精度地识别波长偏移。这项新技术已在对钢工字钢的广泛实验模态分析测试中得到验证,该工字钢的顶部和底部法兰均装有FBG传感器。使用新颖的基于相关的处理技术和常规的峰值跟踪技术,将原始波长FBG数据处理为应变值。随后,应变时间序列用于识别梁的模态特性。最后,广泛研究了两种算法在模态特征识别中的准确性。

著录项

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