正交异性钢桥面板与U肋焊接处应力分布规律研究

Stress distribution of welding foot between orthotropic steel Bridge desk and U-rib

为了分析正交异性桥钢面板中桥面板与U肋焊接部位应力分布规律,以宁波市象山港大桥钢箱梁为研究背景,利用Midas Civil及Midas FEA建立全桥整体及钢箱梁局部节段有限元模型,采用现行《公路钢结构桥梁设计规范》(JTG D64-2015)中的疲劳荷载车模型,依次计算焊脚处桥面板、U肋的纵横向应力及其应力幅,并与现场实测数据进行比较和分析。分析结果表明:疲劳正应力计算结果满足规范要求;疲劳荷载作用下,焊脚处桥面板、U肋纵向应力的交变循环作用对正交异性钢桥面板的疲劳寿命影响更为显著,而横向应力对焊脚处裂缝的产生及发展有一定影响;局部轮压对桥面板应力的影响较大,应以最不利布置(HX2)进行设计计算。

To analyze the stress distribution of wielding foot between orthotropic steel bridge desk and U - rib, the steel box girder of Xiangshan Port Bridge was taken as research background. Based on the finite element model of the integrity of whole bridge and the locality of steel box girder, the stress and stress amplitude of wielding foot was calculated with fatigue traffic load model of Specification for Design of Highway Steel Bridge （ JTG D64 - 2015 ） , and then compared with field - measured data. The results of analysis show that, four kinds of fatigue normal stress satisfy the requirements of specification. Under the fatigue load, the alternating cycle influence of longitudinal stress on the fatigue life of orthotropic steel bridge deck is more significant, however~ the transverse stress have a certain influence on the generation and development of initial cracks in the wielding foot. The most unfavorable arrangement form I HX2 } of wheel pressure should be recommended for design and calculation as a result of higher stress value.