圆形扩孔对摩擦型高强度螺栓承载力影响分析

Influence Analysis of Circular Reaming on Bearing Capacity of Friction-type High Strength Bolts

钢桁梁桥在现场安装时会出现杆件与节点板螺栓孔错开的情况,需对螺栓孔进行扩孔处理。但现有规范中大圆孔的扩孔系数是个与扩孔后直径无关的定值,且未考虑由多块钢板组成构件时,其不同扩孔位置对不同板件的影响。而既有成果仅对长孔和无扩孔结构承载力进行了研究,未考虑钢桥安装过程中的实际情况。为此,针对钢桁梁桥节段螺栓孔扩孔问题,采用Ansys有限元分析方法,对拼接板与中间板全部扩孔、仅中间板扩孔、仅拼接板扩孔等3种工况下螺栓的抗滑力进行分析。结果表明,扩孔直径相同时,全部板件开孔螺栓抗滑力损失最大;仅拼接板扩孔次之;仅对中间板开孔时,滑移荷载降速最小。

The installation of steel truss bridge may lead to the staggered opening of the bolt holes between the members and the joint plate,it is necessary to enlarge the bolt holes.However,in the existing specifications,the expansion coefficient of large circular holes is only a fixed value,which has nothing to do with the diameter of the reamed holes,and does not consider the influence of the location of the reaming holes of the components made up of multiple steel plates on different plates.The existing research results only focus on the bearing capacity of long hole and no reaming structures without considering the actual situation of steel bridge installation process.Therefore,this paper summarizes the use of Ansys finite element analysis software to analyze the anti-sliding force of bolts under three working conditions:all reaming of splice plate and intermediate plate,only reaming of intermediate plate and only reaming of splice plate.The analysis results show that:with the same diameter of reaming hole,1)the loss of anti-slip force of all plate bolt is the greatest;2)reaming of splice plate is second only;3)when only the middle plate is perforated,the slip load drop speed is the smallest.