一次强风作用下大跨度桥梁主梁非平稳抖振可靠性分析  

Reliability analysis of non-stationary buffeting of large-span bridge girder under a strong wind action

作　　者：孙博[1] 叶泽毅 阮伟东 张新军[1] 杨名冠 SUN Bo;YE Zeyi;RUAN Weidong;ZHANG Xinjun;YANG Mingguan(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China;CCCC Highway Consultants Co.,Ltd.,Beijing 100088,China)

机构地区：[1]浙江工业大学土木工程学院,杭州310023 [2]中交公路规划设计院有限公司,北京100088

出　　处：《振动与冲击》2024年第7期144-154,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金(52278226,51908503);浙江省自然科学基金(LY24E080011,LY23E090004);中交集团特大研发项目(KK20043AZY20043A);浙江省公益技术应用研究项目(LGF22E080018);浙江省大学生科技创新活动计划暨新苗人才计划(2023R403081);中国博士后面上基金(2023M733362)。

摘　　要：抖振可靠性评估对保障大型桥梁结构在强风作用下的安全性具有十分重要的意义。在已有研究基础上,基于非平稳风场模型和精细化的抖振时域分析方法,并考虑抖振响应的非平稳性和非高斯特征,构建了大跨度桥梁主梁非平稳抖振可靠性分析的方法流程。非平稳脉动风速的模拟基于进化谱理论采用谐波合成法并引入均匀调制函数来实现。静风力荷载采用规范公式求解,非平稳抖振力采用准定常气动理论并引入气动导纳公式来修正其误差进行模拟,气动自激力通过引入单元气动刚度矩阵与气动阻尼矩阵实现。对于精细化有限元分析得到的抖振响应,采用Winterstein修正模型对其进行高斯转换,并考虑响应方差的时变特性,采用基于Poisson假定的首次超越概率来求解非平稳抖振动力可靠性。应用所提出的方法流程对某大跨度斜拉桥在一次强风作用下的抖振可靠性进行了分析评估,证明了其有效性。Reliability assessment of buffeting is of great significance to ensure the safety of large bridge structures under strong wind conditions.Here,on the basis of existing studies,based on non-stationary wind field model and refined time-domain analysis method for buffeting,considering the non-stationarity and non-Gaussian characteristics of buffeting response,a method flow for reliability analysis of non-stationary buffeting of large-span bridge girder was constructed.Based on evolutionary spectrum theory,simulation of non-stationary fluctuating wind speed was realized using weighted amplitude wave superposition(WAWS)and introducing uniform modulation function.Static wind load was solved using canonical formula.Non-stationary buffeting force was simulated using quasi-steady aerodynamic theory and the aerodynamic admittance formula was introduced to correct its errors.Aerodynamic self-excited force was obtained by introducing element aerodynamic stiffness matrix and aerodynamic damping matrix.For the buffeting response obtained with refined finite element analysis,Winterstein modified model was used to do Gaussian transformation for it.Considering time-varying characteristics of response variance,the first crossing probability based on Poisson assumption was used to solve non-stationary buffeting dynamic reliability.The proposed method flow was applied to analyze and evaluate the buffeting reliability of a certain large-span cable-stayed bridge under a strong wind action to prove its effectiveness.

关 键 词：大跨度桥梁 非平稳风作用 主梁抖振 动力可靠性 时域分析 

分 类 号：U442[建筑科学—桥梁与隧道工程]