基于热点应力法的正交异性钢箱梁疲劳评估  

Fatigue evaluation of orthotropic steel box girder based on hot spot stress method

作　　者：王超[1,2] 朱宏平[1] 钟继卫[2] 

机构地区：[1]华中科技大学土木工程博士后流动站,湖北武汉430074 [2]中铁大桥局集团武汉桥梁科学研究院有限公司,湖北武汉430034

出　　处：《合肥工业大学学报（自然科学版）》2014年第4期449-453,共5页Journal of Hefei University of Technology：Natural Science

基　　金：国家杰出青年科学研究基金资助项目(50925828)

摘　　要：文章运用健康监测系统实测应力数据,采用热点应力法对正交异性钢箱梁进行疲劳评估;并建立了局部有限元模型,计算了疲劳危险焊缝连接部位的应力集中系数。通过实桥健康监测系统采集钢箱梁危险部位的应力时程,运用求出的应力集中系数计算相应的热点应力时程,采用雨流计数法对热点应力进行统计分析得出结构每天的日应力谱,将多天的日应力谱进行统计平均定义为结构标准日应力谱。基于线性累积损伤准则和热点应力疲劳强度曲线对钢箱梁进行疲劳寿命评估,将提出的方法应用于安装了健康监测系统的实桥分析。结果表明,在钢箱梁U肋和横隔板连接的部位会产生疲劳破坏,因此应加强该部位的维修和养护。A method of fatigue evaluation of orthotropic steel box girder based on hot spot stress method is presented by using collected stress data of health monitoring system .The local FEM model of the critical fa-tigue damage component of structure is developed to analyze the stress concentration factor .With the calculat-ed stress concentration factor and the practical strain collected by the health monitoring system ,the hot spot stress can be obtained .Based on the rain-flow counting method ,the standard daily hot spot stress spectrum can be acquired by statistical average analysis of multiple daily stress spectrum .Finally ,the fatigue evaluation of steel box girder is made based on linear cumulative damage criterion and hot spot stress fatigue strength curve .The proposed method is used to evaluate a practical bridge installed with health monitoring system . The analysis result shows that the fatigue damage will occur at the connection part between U-rib and dia-phragm ,w here should be repaired and maintained particularly .

关 键 词：热点应力法 疲劳评估 钢箱梁 应力谱 有限元分析 健康监测 

分 类 号：U446.3[建筑科学—桥梁与隧道工程] TU311.3[交通运输工程—道路与铁道工程]