基于小波分析的跨海大桥斜拉索风致损伤识别

摘要

海域环境下服役的斜拉索要承受强台风、环境腐蚀、重车过桥和温度效应等破坏荷载的作用,可能出现损伤破坏,降低拉索的强度和服役寿命.因此,如何有效快速地识别斜拉索是否发生了损伤,进一步识别出哪根索出现了损伤,这对于桥梁运营养护获得第一手的构件损伤信息是十分重要的.以浙江舟山跨海大桥中的金塘大桥为工程背景,建立了风荷载作用下的斜拉桥数值模型,基于小波分析方法研究了斜拉索损伤对桥面加速度测试信号的敏感性,实现了斜拉索损伤时刻的识别;构建了一种多尺度的损伤指标和损伤位置识别方法,进行了斜拉索损伤位置的识别,并分析验证了这种损伤识别方法的有效性和适用性.%Stayed cables in sea environments have to bear strong typhoon , environmental corrosion ,heavy vehicles ,temperature effects ,and other failure loads .As a result ,damage may occur and the strength and service life of cables structures will reduce . Therefore ,it is very important to effectively find the damage occurred in cables and to identify the damage cable for the operation and maintenance of bridges .A numerical model of cable-stayed bridges under wind loads is established based on the Jintang bridge in Zhoushan Zhejiang .Based on the wavelet analysis method ,the sensitivity of cable-stayed damage to the acceleration test signal of bridge decks is studied and the damage moment is identified .A multi-scale damage index is proposed for identifying the damage locations of cables . The validity and applicability of the damage identification method are verified and analyzed .