基于摄影测量的简支梁桥损伤识别  

Damage Identification for Simple Supported Beam Bridge Based on Photogrammetry

作　　者：李萍[1] 张劲泉[1] 王磊[1] 王陶[1] 闫昕 LI Ping;ZHANG Jin-quan;WANG Lei;WANG Tao;YAN Xin(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;RIOH High Science and Technology Group Co.,Ltd.,Beijing 100088,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]中路高科交通科技集团有限公司,北京100088

出　　处：《公路交通科技》2022年第8期1-8,共8页Journal of Highway and Transportation Research and Development

基　　金：中央级公益性科研院所基本科研业务费项目(2019-0101,2020-9058,2021-9082a);国家重点研发计划课题项目(2018YFB1600305)。

摘　　要：曲率模态法是检测结构损伤的重要方法之一,但是在推广应用的过程中,受到传感器数量的限制,检测精度不高。摄影测量法可以非接触获得较为密集的测点数据,突破该方法的应用限制。采用图像相关法(DIC)处理结构振动视频数据,提取视频流中各标识点的竖向动态位移时程数据。通过时频转换确定结构的主频和振型,通过中心差分法得到曲率模态。在损伤尺度不变的情况下,按照不同测点间距提取测点的振型和曲率,对比了测点间距对曲率模态法检测损伤突变的影响。计算了不同测点间距的曲率模态差、曲率模态变化率,验证了二者对于曲率突变的放大效应。通过分析简支梁振动试验的结果可知:有损/无损梁的曲率模态曲线都不光滑;在测点间距比较密时,损伤位置的曲率突变很大,可检测损伤位置,但是依据单一状态的曲率模态判断损伤容易受到其他突变的干扰;不同状态的曲率模态对比更易于判断损伤位置;曲率模态变化率、曲率模态差能在一定程度上放大损伤位置的曲率突变,但是放大效应有限。由此可知,提高损伤检测定位精度最有效的方式是加密提取测点,将不同损伤状态的曲率模态做比对。比较而言,摄影测量法比传统的测量手段更适用于求解曲率模态的损伤指标,在降低检测成本的同时,使检测更加便捷高效。Curvature modal method is one of the important methods for detecting structural damage,but in the process of promoting its application,it is limited by the number of sensors and the detection accuracy is not high.Photogrammetry allows non-contact acquisition of more dense measuring point data,breaking the application limitations of the method.The structural vibration video data are processed and the vertical dynamic displacement time course data of each marker point in the video stream are extracted by using the digital image correlation(DIC) method.The principal frequency and vibration modes of the structure are obtained by time-frequency conversion,and the curvature modes are obtained by the central difference method.The vibration mode and curvature are extracted according to different spacings of the measuring points with constant damage,the influences of measuring point spacing on damage mutation detection by curvature modal method are compared.The curvature mode differences and curvature mode change rates for different measuring point spacings are calculated,and the amplification effect of the 2 methods on the curvature mutation is verified.By analyzing the result of vibration test on simply supported beams,it can be seen that(1) the curvature modal curves of both damaged/undamaged beams are not smooth;(2) when the distances between measuring points are relatively dense,the curvature of the damage location has a large mutation,and the damage location can be detected,however,the damage detection is easily disturbed by other mutations based on the curvature mode of single state;(3) comparison of curvature modes in different states makes it easier to determine the location of damage;(4) the curvature modal change rate and curvature modal difference can amplify the mutation of curvature at the damage location to a certain extent,but the amplification effect is limited.Thus,the most effective way to improve the localization accuracy of damage detection is using more extraction points and compare the curvature mod

关 键 词：桥梁工程 损伤检测 非接触测量 曲率模态 曲率变化率 

分 类 号：U446.3[建筑科学—桥梁与隧道工程]