芜湖长江大桥钢梁整体节点疲劳试验研究

Steel Beam Integral Node Fatigue Test of Wuhu Yangtze River Bridge

芜湖长江大桥采用国内新研制的经微合金化处理的 14MnNbq中强钢 ,最大板厚达 5 0mm。采用先进的焊接整体节点。不同的构造细节形式 ,采用不同的焊接方法和工艺 ,具有各不相同的受力特性、残余应力分布和应力集中程度。文中以应力幅值σr 为参数 ,对节点模型试验区内的 6处等宽不等厚的对接焊缝 ,以及 (棱 )角焊缝、对接焊缝与 (棱 )角焊缝交叉、平联节点板、隔板角焊缝、节点板圆弧部位进行了试验分析。测量了节点应力分布 ,通过对节点施加疲劳荷载 ,分析整体节点各构造细节的疲劳强度 ,对整体节点的抗疲劳性能给出了总的评价 ,认为该桥梁的整体节点各构造细节布置合理 ,焊接及制造工艺先进 ,各种构造细节均有足够的抗疲劳强度。

The Wuhu Yangtze River bridge adopts the 14MnNbq medium strong steel treated with a newly developed Chinese micro-alloy technology. The thickest plate is 50 mm. Advance welding integral node is used. Welding methods and techniques vary with structure details and result in different force bearing features, residual stress distributions and stress concentrations. The paper analyzes, with the reference of stress amplitude being (r, the bud welding seam in different thickness, the corner welding, the crossing of the bud welding and the corner welding seam, the flat connected node plate, the insulation plate corner welding seam and the node plate arch in the node model test zone. The node stress distribution is measured. It is by applying fatigue loading to the nodes that we analyze the fatigue intensity of the each structure detail of the integral node. Thus we get a general assessment of the anti fatigue performance of the integral node. We come to the conclusion that various structure details of the integral node are reasonably distributed, the welding and manufacturing technique are advanced and the various structure details have sufficient anti fatigue intensity.