标准化Z字形钢结构梁柱连接节点转动刚度研究

Research on Rotational Stiffness of Standard Z-Shaped Steel Beam-Column Connections

为研究标准化Z字形钢结构梁柱连接节点的转动刚度,对翼缘焊接和搭接两种形式的Z字形钢结构梁柱连接节点进行了单调和往复循环加载试验及有限元分析。研究了不同连接节点设计强度对Z字形钢结构梁柱连接节点转动刚度和循环刚度退化等力学性能的影响。结果表明,翼缘焊接和搭接两种形式的Z字形钢结构梁柱连接节点均具有良好的延性和滞回性能。翼缘焊接Z形节点转动刚度表现为刚性连接,翼缘搭接Z字形钢结构节点转动刚度表现为铰接。对于翼缘焊接Z字形钢结构梁柱连接节点,其转动刚度和循环刚度退化程度受焊缝连接强度影响显著。较小的强度设计倍数(0.2~0.4)时节点破坏模式为焊缝率先发生破坏,其节点转动性能表现为半刚性。较大节点强度设计倍数(0.7~1.1)时节点破坏模式转变为构件率先发生破坏,节点表现为刚性连接且其循环刚度退化程度(转角小于0.02 rad条件下)明显小于强度设计倍数较小的Z字形钢结构节点循环刚度退化程度。总体上看,可通过改变节点强度设计倍数来调节其转动刚度。

To investigate the rotational stiffness of standard Z-shaped steel beam-column connections,the monotonic and cyclic loading experiments and finite element analysis of Z-shaped beam-column connections with flange welding and lap are conducted.The effects of different design strength on the mechanical properties of Z-shaped connections,such as rotational stiffness and cyclic stiffness degradation,are studied.The results show that both flange-welded and flange-lapped Z-shaped connections have good ductility and hysteresis performance.The rotational stiffness of the flange-welded Z-shaped connection has rigid characteristics,and that of flange-lapped Z-shaped connection is hinged.For the flange-welded Z-shaped connections,the welding designed strength has a significant effect on the rotational stiffness and cyclic stiffness degradation.The smaller designed strength parameter(0.2~0.4)results in that the failure mode of Z-shaped connection is premature damage of weld,and the rotational performance of the Z-shaped connection is semi-rigid.In case of the larger designed strength parameter(0.7~1.1),the failure mode is changed to the premature damage of the connected member,and the rotational performance of the Z-shaped connection is rigid.In addition,the degree of cyclic stiffness degradation of Z-shaped connections(rotational angle less than 0.02 rad)is obviously smaller than that of Z-shaped connections with smaller designed strength parameter.In general,the rotational stiffness can be adjusted by changing the designed strength parameter of Z-shaped connections.