钢桁梁桥高强螺栓连接的节点板局部受力性能分析

Analysis on Local Mechanical Properties of High Strength Bolt Gusset Joints in Steel Trussed Girder Bridges

针对重载运输过程中出现的既有线钢桁梁桥高强螺栓节点螺栓断裂问题,以长东黄河桥为工程背景,采用ANSYS软件建立了带螺栓的实际节点板局部有限元模型,对其在轴力作用下的传力性能进行了研究,并分析了螺栓缺失所造成的影响。结果表明:长列高强螺栓接头在轴力作用下各排传力比呈马鞍型分布;在螺栓连接的计算中应考虑一排内螺栓传力的不均匀性;螺栓缺失后只对局部范围内的螺栓传力比有影响,影响最大的是其相邻的两排螺栓,但若传力比较大的螺栓排缺失数量达到一定程度后,极易使剩余螺栓所受剪力超过其抗剪承载力而出现剪切破坏。

In order to solve the problem of bolts missing of the frictional high strength bolted gusset joints in existing steel trussed girder bridges under overload transportation, the local finite element model of an actual gusset plate with bolts is built by software ANSYS, the transfer performance under axial load is studied and the influence of bolts missing is analyzed based on Changdong Yellow River Bridge. The results are as follows： The regularities of load transfer factors of the high strength bolt friction grip long joint under axial load is of saddle type distribution, while the uneven arrangement of the bolts in actual gusset plate leads to the mutations of load transfer factors in individual locations ; In the calculation of bolted connections, the inhomogeneity of load transfer within a row should be considered; The bolt missing only has an impact on load transfer factors in the local scope, and the most affected are the adjacent two rows, but if the number of missing bolts in rows with large load transfer factors reaches a certain degree, it is easy to make the rest of the bolts subject to shear over capacity and cause shear failure.