中文摘要：

正交异性钢桥面板焊接部位疲劳问题突出,为研究采用新型镦边U肋替代传统U肋,其与正交异性钢桥面板焊缝处的应力改善情况,以典型正交异性钢桥面板为研究对象,按照实际尺寸参数采用ANSYS有限元软件建立足尺节段模型进行分析。确定关注区域及最不利荷载加载位置,在此基础上,建立焊缝局部精细模型,采用切口应力法分析镦边U肋与面板焊缝和传统U肋与面板焊缝在焊趾及焊根部位的应力。结果表明：采用镦边U肋与传统U肋在U肋与面板焊缝处应力分布基本相似;相对于传统U肋焊缝,镦边U肋焊缝在面板焊趾、焊根和U肋焊趾处应力最大降幅分别为24.3%、43.8%、60.5%,镦边U肋可以较好地改善U肋与面板焊缝处的应力集中效应,有利于提高结构的抗疲劳性能。

英文摘要：

The fatigue problem of the welded connection of the orthotropic steel bridge deck plate is notable.To study the improvement of the stress in the welded connection of the U-rib and the deck plate by way of replacing the conventional U-rib with the new type of the edge upset Urib,a typical orthotropic steel bridge deck plate was taken as the research object,the finite element software ANSYS was used to set up the full-scale sectional model for the deck plate according to the actual dimension parameters and the analysis of the model was correspondingly conducted.The areas of concern and the worst loading positions of the deck plate were determined,the refined model for the local part of the welded connection was established and the stress in the weld toes and weld roots of the welded connections of the edge upset U-rib and the deck plate and of the conventional U-rib and the deck plate were analyzed,using the notch stress method.The results demonstrate that the stress distribution respectively at the welded connections of the edge upset U-rib and the deck plate and at the conventional U-rib and the deck plate is basically similar.Compared to the welded connection of the conventional U-rib,the maximum stress decrease amplitude of the welded connection of the edge upset U-rib in the weld toe and weld root of the deck plate and in the weld toe of the U-rib is respectively 24.3%,43.8% and 60.5%.The edge upset U-rib can well improve the stress concentration effect of the welded connection of the U-rib and the deck plate and is conducible to the improvement of the fatigue performance of the structure.