竖向荷载下半刚性连接组合框架梁的承载能力极限状态设计

论述了半连续框架设计原理,提出用塑性分析方法计算竖向荷载下半刚性连接组合框架梁在承载能力极限状态的内力,并给出了具体的设计步骤,最后用两榀足尺的两层两跨的半刚性连接组合框架试验验证了塑性分析方法。研究表明,半连续框架设计可用塑性分析方法获得弯矩图,不同于连续框架设计用弹性分析方法获得弯矩图;塑性分析方法考虑了组合梁的跨中弯矩承载力、节点弯矩承载力、节点转动能力和设计需要的节点转动能力,适用于竖向荷载下半刚性连接组合框架梁的承载能力极限状态设计。该方法简单实用且比较准确,可供工程设计参考。

Design of beams for semi-rigid composite frames at ultimate limit state under vertical loads

The design principle of beams for semi-continuous frames is discussed in this paper.Plastic analysis method is presented to calculate the internal forces of the beams for a semi-rigid composite frame under vertical loads at ultimate limit state,and the design procedure is also presented.Finally,the plastic analysis method is verified by the experimental results of two full-scale semi-rigid composite frames with two-stores and two-spans.It has been found that:(1) Bending moment diagram attained by the plastic analysis method in the semi-continuous design is different from that attained by elastic analysis method in the continuous design.(2) Considering beam sagging moment capacity,joint moment capacity,joint rotation capacity and required rotation capacity,the plastic analysis method is suitable for the design of beams for semi-rigid composite frames under vertical loads at ultimate limit state.It is also found that the proposed method is simple and convenient for the structural design in a practical engineering.