摘要
为研究斜拉桥钢箱梁纵桁架疲劳特征,建立了钢箱梁节段有限元模型,通过选取评判开裂细节疲劳性能的主导应力,确定最不利加载工况.在此基础上,分析了纵桁架局部应力梯度、疲劳起裂点正应力时程以及主应力流.研究表明:局部应力梯度表明应力随着与连接端距离的增大而呈现降低趋势;两类疲劳起裂点处的正应力时程表明面内变形是引起角钢斜撑疲劳开裂的主导变形;角钢疲劳裂纹的扩展方向与荷载位于最不利位置时的绝对值最大主应力的方向相垂直.
In order to study the fatigue characteristics of longitudinal truss of steel box girder of cable-stayed bridge,a segmental finite element model of steel box girder was established.By selecting the dominant stress to judge the fatigue performance of cracking details,the most unfavorable loading condition was determined.On this basis,the local stress gradient,normal stress time history of fatigue crack initiation point and principal stress flow of longitudinal truss were analyzed.The research shows that the local stress gradient indicates that the stress decreases with the increase of the distance from the connecting end.The time history of normal stress at two fatigue crack initiation points shows that in-plane deformation is the dominant deformation causing fatigue crack of angle steel brace.The fatigue crack propagation direction of angle steel is perpendicular to the direction of absolute maximum principal stress when the load is at the most unfavorable position.
作者
李心诚
傅中秋
王赞
章郝明
吉伯海
LI Xincheng;FU Zhongqiu;WANG Zan;ZHANG Haoming;JI Bohai(College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China)
出处
《武汉理工大学学报（交通科学与工程版）》
2021年第5期935-938,944,共5页
Journal of Wuhan University of Technology（Transportation Science & Engineering）
基金
国家自然科学基金面上项目(51678215)、江苏苏通大桥有限责任公司科技项目(2019)。
关键词
钢箱梁
纵桁架
疲劳应力
有限元模型
应力特征
steel box girder
longitudinal truss
fatigue stress
finite element model
stress characteristic
