钢箱梁横隔板弧形切口疲劳性能及构造优化研究  

Study of Fatigue Performance and Structural Optimization of Arc-Shaped Notch in Diaphragm of Steel Box Girder

作　　者：何志刚[1] 蔺鹏臻[1] HE Zhi-gang;LIN Peng-zhen(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《桥梁建设》2021年第1期37-43,共7页Bridge Construction

基　　金：国家自然科学基金项目(11790281);国家自然科学基金高铁联和项目(U1934205)。

摘　　要：为评估正交异性钢桥面板的疲劳寿命,给维修和设计提供参考,以某连续钢箱梁桥(设置高1.8m的横隔板与净高0.9m的横肋)为背景进行研究。采用ANSYS子模型技术建立了钢箱梁节段模型,基于热点应力法对横隔板与横肋弧形切口起始处和弧形切口自由边两处疲劳细节进行了寿命预测,并就两处细节疲劳性能对弧形切口型式和板厚变化的敏感性进行了分析。结果表明:随横肋高度增加,弧形切口两处细节的疲劳性能对于板厚变化的敏感性增强;随弧形切口曲率比增大,弧形切口起始处的计算寿命增加,而弧形切口自由边的计算寿命减小;优化后横隔板与横肋的弧形切口的曲率比分别取3.33和4.29、板厚分别取12mm和8mm,较原设计切口型式,优化后可将横隔板与横肋的弧形切口的计算疲劳寿命分别延长7.8年和9.6年。To predict the fatigue life of the orthotropic steel deck plates and provide references for maintenance and design,a continuous steel box girder bridge that are equipped with 1.8m-deep diaphragms and transverse ribs of 0.9mnet depth is taken as a study case.The segmental model of the steel box girder was established by ANSYS,using the submodelling technique.Based on the hot-spot stress method,the fatigue details at the starting point of the arc-shaped notches in the diaphragm and the transverse rib as well as the free edges of the arc-shaped notch were examined,and the influence of arc-shaped notch patterns and plate thickness on these two types of fatigue details was analyzed.The results show that as the depth of transverse rib increases,the fatigue performance of these two types of fatigue details becomes more sensitive to the variation of plate thickness.With the increase of curvature ratio,the calculated life of fatigue details of the starting point of arc-shaped notch is extended,but the calculated life of the free edges of arc-shaped notch is decreased.After optimization,the curvature ratios of the arc-shaped notches in diaphragms and transverse ribs are set at 3.33and 4.29,with plate thicknesses of 12mm and 8mm,respectively.Compared to the original type of arc-shaped notch,the calculated fatigue life of the optimized arc-shaped notches in diaphragms and transverse ribs can be extended by 7.8and 9.6years,respectively.

关 键 词：正交异性钢桥面板 横隔板弧形切口 热点应力 疲劳寿命 曲率比 多目标约束优化 有限元法 

分 类 号：U443.32[建筑科学—桥梁与隧道工程] U441.4[交通运输工程—道路与铁道工程]