斜拉桥结构施工状态下连续小波变换损伤识别方法  

Damage identification based on continuous wavelet transformation for a real cable-stayed bridge structure under construction condition

作　　者：唐雪松[1] 谭珂[1] 陈星烨[1] 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410004

出　　处：《长沙理工大学学报（自然科学版）》2010年第1期31-38,共8页Journal of Changsha University of Science and Technology:Natural Science

基　　金：教育部高校博士点基金资助项目(200805360002)

摘　　要：以在建的广东李家沙特大斜拉桥为工程背景,选取双悬臂施工状态下的结构为分析对象,利用MI-DAS软件分析获得结构的各阶振动模态,将之作为输入信号导入MATLAB中,进行Gaussian小波变换用于结构损伤识别.对不同位置与程度结构损伤的识别效果进行了讨论,对各阶模态及各类型模态的损伤识别效果进行了比较,并考虑了随机噪声的影响.研究结果表明,曲率模态对结构损伤较为敏感,损伤识别的效果较好.另外,损伤识别效果受一定边界条件的影响.但总的来说,曲率模态的连续小波变换信号能够快速、可靠地识别出施工过程中结构的损伤位置与损伤程度.The structural damage during the construction process is often neglected.Lijiasha Bridge is a large-span cable-stayed bridge and is now under construction in Guangdong province.A structure under the bi-cantilever construction condition is selected to set up the analytical model.The structural modal analysis is performed to obtain the structural modal shapes by using the FEM software MIDAS.Then,the modal shapes are input into the software MATLAB as the input singles to perform the Gaussian wavelet transformation which is applied to the damage identification.The identification results for different damage location and degree are discussed and compared by using different order and type of modal shapes.Meanwhile,the random white noise is taken into account in the analysis.The result indicates that the curvature mode is sensitive to the structural damage condition and the detection effect is satisfied.However,the detection effect would be affected by the structural boundary conditions.In general,the continuous wavelet transformation of the curvature modes has an ability to quickly and reliably identify the damage location and degree of the structure in the construction process.

关 键 词：桥梁结构 损伤识别 施工状态 连续小波变换 模态振型 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]