铁路钢箱梁正交异性桥面加劲肋疲劳性能研究

甬江特大桥是国内首座铁路大跨度钢箱混合梁斜拉桥。目前国内外大部分疲劳模型试验研究都仅针对单一纵肋形式下正交异性钢桥面板的疲劳特性,不同纵肋形式下的对比研究较少。因此,结合弗拉索夫薄壁杆件理论,提出了加劲肋疲劳敏感部位面内疲劳应力的解析公式,分析了解析公式各疲劳影响因素的影响程度及作用机理,并同有限元模拟及2U+2V模型测试结果进行对比分析。研究表明:解析公式结果同有限元模拟以及试验测试结果一致,其中V型加劲肋疲劳敏感部位疲劳应力小于U型加劲肋,模型试验中U型加劲肋疲劳敏感部位出现裂纹,因此,在铁路列车荷载作用下,V型加劲肋疲劳敏感部位比U型加劲肋具有更好的抗疲劳性能。

Research on Fatigue Performance of Orthotropic Bridge Deck Stiffeners for Railway Steel Box Girder

Yongjiang Bridge is the first large span steel box composite girder cable-stayed railway bridge in China.At present,most of the fatigue models in China and the world only focus on the study of the fatigue properties of orthotropic steel bridge panels under single longitudinal ribs,rather than comparative studies on orthotropic steel bridge panels under different longitudinal ribs.Therefore,based on the theory of Velassov's thin-walled bar analysis,an analytical formula of the in-plane fatigue stress in the fatigue-sensitive parts of the stiffener was proposed.The influence and the mechanism of the fatigue factors were analyzed,and compared with the results of the finite element simulation and 2U+2V model experiment.The results show that the results of the analytical formula are consistent with those of the finite element simulation and the experiment.The fatigue stress of the V-type stiffener is less than that of the U-shaped stiffener.Cracks appear in the fatigue sensitive part of the U-shaped stiffener in the experimental model.It can be concluded that under the action of the train load,the fatigue sensitive part of the V-type stiffener shows better anti-fatigue performance than the U-shaped stiffener.