平端板连接半刚性梁柱组合节点的抗弯承载力Ⅰ:负弯矩作用

基于现有试验数据以及组合节点抗弯承载力的研究成果,利用塑性分析方法和组件法,提出一种平端板连接组合节点承受负弯矩作用时,其塑性抗弯承载力的计算方法。探讨组合节点的实效模式,给出其各组件承载力的计算方法,组件包括钢筋、螺栓、柱腹板、梁翼缘、混凝土楼板等。考虑中和轴出现的6种位置:混凝土楼板内;钢梁上翼缘内;钢梁腹板内,所有螺栓受压;前m-1排螺栓受拉,第m排部分受拉,其余受压;1～m排完全受拉;只有钢梁下翼缘受压。该方法可以考虑节点承受非对称荷载作用的情况以及作用在连接上的剪力、高强度螺栓撬力等因素的影响。如果将组合连接的配筋率取为零,不考虑组合楼板的影响,使用该方法同样可以计算平端板连接梁柱纯钢节点在承受负弯矩作用时的抗弯承载力。

Moment capacity of semi-rigid composite beam-column joints with flush end plate connections:Ⅰ. under negative moment

Based on the experimental results, a method has been developed for predicting the moment capacities of flush end-plate composite connections under negative moment, by using plastic analysis method and component method. Possible failure of the composite connections and resistance of the components are provided. Six locations of plastic natural axis are considered when determining the connection moment capacity, including: plastic natural axis in the slab, in the upper flange of the steel beam, in the beam web and all the bolt rows are in the compression zone, bolt rows up to(m-1)are fully in tension and bolt row m is partially in tension with other bolt rows being in compression, bolt rows 1 to m are fully in tension, and only the bottom flange of the steel beam is in compression. The effects of non-symmetrical moments, shears on the connections and prying forces of high-strength bolts are taken into account. If the reinforcement ratio is set as zero without considering the effect of the composite slab, then the moment capacity of bare steel connections can also be predicted by using the developed method.