基于悬挂式FBG的螺栓连接微小扭矩检测  

Small Torque Detection of Bolt Connection Based on Suspended-FBG

作　　者：饶春芳 陈鹏 胡友德[2] 詹学峰 姜子薇 王跃翔 余文鑫 RAO Chunfang;CHEN Peng;HU Youde;ZHAN Xuefeng;JIANG Ziwei;WANG Yuexiang;YU Wenxin(Jiangxi Key Laboratory of Communication and Optoelectronics,College of Physics and Communication Electronics,Jiangxi Normal University,Nanchang 330000,China;Department of Stomatology,Jiangxi Provincial People's Hospital,Nanchang 330000,China;BYD Company Limited,Shenzhen 510000)

机构地区：[1]江西师范大学物理与通信电子学院,江西省光电子与通信重点实验室,南昌330000 [2]江西省人民医院口腔科,南昌330000 [3]比亚迪股份有限公司,深圳510000

出　　处：《光子学报》2024年第4期130-138,共9页Acta Photonica Sinica

基　　金：国家自然科学基金(No.12064016);江西省自然科学基金(No.20212BAB202019);江西省卫生健康委科技计划(No.202110009);江西省教育厅科学技术研究项目(No.GJJ200311)。

摘　　要：将光纤布拉格光栅通过尾纤悬挂在带螺栓连接的结构件表面,使用结构动态检测法测试螺栓连接结构的扭矩。测试中,在待测结构件上产生周期性的振动,在振动的作用下尾纤中产生周期性应变,它作为波源在刻有布拉格光纤光栅的光纤中形成应力波,布拉格光纤光栅感知应力波形成测试信号。在识别过程中,首先使用经验模态分解方法对测试信号进行分解以去除不平稳分量及噪声,然后提取信号的有量纲和无量纲特征值,最后将这些特征值输入基于支持向量机的识别系统。结果表明,该方法识别正确率达97.2%,扭矩识别能力在N·cm量级。本研究开拓了一种新的螺栓连接状态的检测方法,尤其适用于小质量结构中微小扭矩的检测。Loosing of the bolt connection structure affects its working and operation safety.The main reasons for the loosing coming from loading,vibration,and friction.Consequently,loosing is inevitable and its monitoring is important for its application.At present,the theory and technology of testing the tightness state of bolt connection are still not mature.The detection of small torque is a technical difficulty in this field.In this study,for the structure to be tested on the uneven surface in the narrow space,the Bragg Fiber Grating(FBG)was used as the sensor to identify the small torque of the bolt connection.In the testing,a periodic vibration in the tested structure with bolt tightness information was excited and employed for the identification.One tail of the suspended-FBG was sticked on the tested structure,and the vibration yielded periodic strains in the tail of the FBG,which acted as the source of the elastic longitudinal wave propagating along the optical fiber with a FBG written in it.The edge-filter method was used to demodulated the signals in the FBG sensor to satisfy the high frequency signals.The information coming from the FBG was used to be identified.Firstly,the Empirical Mode Decomposition(EMD)method was used to decompose the original signal,basing on which,we removed the unstable components and noise by calculating the correlation function of each component and the original signal.Then the signals were restructured for later identification.The dimensional features(standard deviation,residuals,peak-peak value,and energy)and dimensionless features(skewness,kurtosis,waveform factor,amplitude factor,impact factor and margin factor)of the signals were exacted,and were inputted to the recognition system based on the Support Vector Machine(SVM)finally,where we used the ten-fold cross-validation algorithm and Gaussian kernel function SVM for higher accuracy.Results show that the recognition accuracy reaches to 97.2%and the torque recognition ability is on the order of N·cm.This study proves that optical f

关 键 词：螺栓扭矩识别 结构动态检测 悬挂式光纤布拉格光栅 经验模态分解 支持向量机 

分 类 号：TN253[电子电信—物理电子学]