组合桥面板球扁钢加劲肋螺栓接头力学性能

Mechanical Behavior of Bulb Flat Rib Bolted Joints in Composite Bridge Decks

为了研究组合桥面板中球扁钢加劲肋的高强螺栓接头的力学性能,设计制作了2个采用双面对称拼接板螺栓接头的组合板试件,通过疲劳和静力加载试验测试了螺栓接头的受力性能,并采用有限元模型对接头进行受力分析。试验及有限元结果表明:该种螺栓接头抗疲劳性能良好,正常使用状态下螺栓拼板连接效果受试验疲劳加载的影响很小;受球扁钢非对称截面特点的影响,螺栓拼板接头呈非对称弯曲,球头一侧的拼接板中间底部受力可比基于平面弯曲计算的应力值高出55%,值得在设计接头时注意;组合桥面板螺栓接头处截面的极限承载力由混凝土压溃控制,螺栓出现滑动后的承载力尚有相当的富余。

In order to study the mechanical properties of the bolted joint of bulb flat ribs applied in composite bridge decks,two full-scale composite deck specimens with bolted joint of symmetric splice plates were designed and submitted to fatigue and static tests.Besides,a finite element model was established to analyze the stress state of the bolted joint.The test and finite element analysis results show that the bolted joint has a high fatigue cracking resistance and the bolted connection stays sound after the given fatigue load cycles in this paper.In addition,due to the asymmetric cross-section,the bolted joint features an asymmetric flexural state,which results in a 55%higher stress level of the bottom on mid-section of the splice plate installed on the side of bulb compared to the calculated value based on the plane bending theory.Moreover,the ultimate bending bearing capacity of the cross section in the bolted joint is dominated by concrete crush and shows a large margin after the occurrence of the bolt slip.