钢桁梁悬索桥整体节点数值疲劳研究

Numerical Fatigue Study on Integral Joints of Steel Truss Suspension Bridge

以湖北白洋长江大桥为工程背景,采用数值模拟的方式开展钢桁架整体节点疲劳性能研究。文中基于有限元软件midas Civil建立全桥模型,采用推导得到的482 kN标准疲劳车加载,确定最不利节点位置。基于英国规范BS5400和Miner线性累积损伤理论公式,计算得到最不利节点各杆件200万次等效轴力辐。使用ANSYS Workbench建立1∶4缩尺模型,对整体节点进行数值疲劳分析。结果表明,整体节点疲劳试验过程中,最小疲劳寿命为200万次,最小的疲劳安全系数为1.26,大于最低值1,故该整体节点的疲劳性能满足设计要求。

Taking Baiyang Yangtze River Bridge in Hubei Province as the engineering background,the fatigue performance of steel truss integral joints is studied by numerical simulation.Based on the finite element software midas Civil,the whole bridge model is established,and the 482 kN standard fatigue vehicle load,a derived value,is used to determine the most unfavorable node location.Based on the British code BS5400 and miner's linear cumulative damage theory formula,two million equivalent axial force spokes of each member of the most unfavorable joint are calculated.On the basis of the similarity theory,a 1∶4 scale model is designed,and the ANSYS Workbench is used to analyze the numerical fatigue of the whole joint.The results show that the minimum fatigue life of the whole joint is 2 million times,and the minimum fatigue safety factor is 1.26,which is greater than the minimum specified value of 1.It is concluded that the fatigue performance of the whole joint meets the design requirements.