钢板梁桥水平节点板腹板间隙面外变形疲劳应力分析

Analysis of Out-of-plane Deformation and Fatigue Stress of Horizontal Gusset Plate Web Gap of Steel Plate Girder Bridge

分别对直桥、斜桥以及弯桥进行全桥三维数值模拟,分析各类钢板梁桥水平节点板的腹板间隙疲劳应力分布。通过对各类结构参数对疲劳性能的影响进行分析,计算结果表明:在车辆荷载的作用下,水平节点板的腹板间隙处存在面外变形,在腹板-加劲肋焊趾引起较大的纵向拉应力,极易萌生疲劳裂纹;腹板间隙、腹板厚度、节点板形式、桥梁跨径、斜交角、平曲线半径等因素对面外变形与疲劳应力的影响较大,节点板厚度和平联刚度对面外变形与疲劳应力几乎无影响。

Most of the fatigue cracks of steel bridges in operation are caused by out of plane deformation.The web clearance details of horizontal gusset plates are one of the main out of plane deformation fatigue details of steel plate girder bridges.In this paper,the three-dimensional numerical simulation of straight bridge,inclined bridge and curved bridge is carried out respectively to analyze the fatigue stress distribution of web gap of horizontal gusset plates of various steel plate girder bridges and the infl uence of various structural parameters.The results show that,under the action of vehicle load,there is out of plane deformation at the web gap of horizontal gusset plate,which causes large longitudinal tensile stress at the web stiff ener weld toe,and fatigue cracks are easily initiated;Web clearance,web thickness,gusset plate form,bridge span,skew angle,horizontal curve radius and other factors have a greater impact on external deformation and fatigue stress,while gusset plate thickness and fl at stiff ness have little impact on external deformation and fatigue stress.