带悬臂梁段连接的梁柱节点初始转动刚度研究

Initial rotational stiffness of semi-rigid connections in steel column-tree moment-resisting frames

对带悬臂梁段拼接连接和栓焊连接的两类节点进行理论计算、试验研究和数值分析,研究节点域和拼接区两部分的受力性能,探讨带悬臂梁段连接的梁柱节点的刚度及其初始转动刚度计算模型。基于相关性对带悬臂梁段连接节点进行不确定性结构灵敏度分析,构建只含几何参数的节点初始转动刚度计算模型。分析表明,两类连接节点和全焊接连接节点具有一定半刚性;在拼接区具有足够连接强度时,带悬臂梁段连接节点与全焊连接节点的弹性阶段初始转动刚度表现出较好的一致性,弹塑性阶段力学性能也相近;从计算模型中可以直接看出各参数对初始转动刚度的敏感程度。通过计算实例表明,对钢框架进行设计时,按半刚性设计比考虑节点域剪切变形的刚性设计偏于安全;依据提出的节点初始转动刚度计算模型进行带悬臂梁段连接的钢框架半刚性设计较为准确。

The theoretical calculation,experimental research and numerical analysis were conducted on two beamcolumn connections with cantilever beam splicing( fully splicing connection and flange welded-web bolted connection). The semi-rigid behavior was studied for joint region and splicing area. The stiffness characteristics and calculation model of initial rotational stiffness were discussed for semi-rigid connections in steel column-tree momentresisting frame. The structural probabilistic sensitivity analysis was conducted for the two beam-column connections with cantilever beam. A new calculation model including geometric parameters for the initial rotational stiffness of the beam-column connections with cantilever beam was proposed. The results show that the two beam-column joints and fully welded joint have semi-rigid characteristic; when the splicing area has sufficient strength,the initial rotational stiffness of the two beam-column connections with cantilever beam are in good agreement with the initial rotational stiffness of fully welded joint within the elastic range of the connections and the mechanical behavior of beam-column connections with cantilever beam and fully welded joint are relatively close within the elasto-plastic range of the connections; the effect of key parameters on the initial rotational stiffness can be clearly reflected in the model. The calculation example shows that,semi-rigid design is safer than rigid design with considering shear deformation in joint region for steel frame design; it is more accurate to do semi-rigid design with the calculation model of the initial rotational stiffness for the semi-rigid connections in steel column-tree moment-resisting frame.