正交异性钢桥面板栓焊接头疲劳性能研究

Fatigue Behaviour of Bolt-Welded Joints for U-Ribs in Orthotropic Steel Bridge Decks

摘要:

针对正交异性钢桥面板现场栓焊连接细节，设计制作2个足尺模型试验构件，并完成疲劳试验。采用有限元分析方法建立了构件计算模型，计算分析发现纵肋螺栓接头中面外弯矩影响明显，内侧拼接板受力大于外侧。拼接板中纵向应力呈鞍状分布，中间区域应力大于两端，两个试验构件的疲劳裂纹也在内侧拼接板的中间区域首先出现。建议栓焊接头按EUROCODE中的71级或铁路桥梁钢结构设计规范中IX细节进行疲劳设计。通过有限元模拟计算，对拼接板进行优化设计，改善了栓焊接头的疲劳性能。

Abstract:

Two full scale specimens of orthotropic steel decks with on-site bolt-welded U-rib connection detailing were designed and fabricated, and then the fatigue tests were conducted. A FE model of bolt-welded joints for the orthotropic steel bridge decks was proposed. The FE analysis showed that the longitudinal stresses in the inner connection plate were higher than those in the outer connection plate, and the stresses were influenced by the out of plane bending in the bolted U-rib joints. Stress distribution along the axial direction of the connection plate appeared a saddle-like shape. The stresses in the center region were higher than those in the end, which led to the fact that fatigue cracks appeared earlier in the center region of the inner connection plate in the both specimens. It is suggested that the fatigue strength of bolted U-ribs joint in the orthotropic steel decks be evaluated based on the fatigue design curve of category 71 in EUROCODE or the fatigue design curve of category IX in the Code for Design of Steel Railway Bridges. A parameter study base on FE analysis was further developed to optimize dimensions of the bolt connection plates and to improve the fatigue performance of the steel bridge decks.