冷弯薄壁方钢管梁柱加腋节点抗震性能研究  

Experimental research on seismic behavior of beam-column connection with welded haunch in cold-formed thin-walled square steel tube structure

作　　者：张春涛[1] 李正良[1,2] 王汝恒[3] 贾彬[1,3] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]西南科技大学土木工程与建筑学院,绵阳621010

出　　处：《振动与冲击》2012年第15期60-67,78,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50908243);国家高技术研究发展计划(863)项目(2009AA032304)

摘　　要：汶川地震后在灾区重建过程中大量使用冷弯薄壁方钢管,但其梁柱节点的连接方式和力学性能等尚需进一步研究。基于结构实际受力情况设计了一种三维双节点试验模型,对不同轴压比下冷弯薄壁方钢管梁柱加腋节点和普通节点的8个试件进行了足尺试验,通过对比分析研究了低周往复荷载作用下加腋节点的破坏模式、滞回曲线及评价节点抗震性能的主要参数(承载力、延性、刚度退化和能量耗散系数等)。同时,利用ANSYS对各节点进行了有限元数值计算,并与试验结果进行对比分析进一步对加腋节点进行了研究。结果表明:试验与有限元数值计算结果吻合良好,验证了理论分析的正确性;加劲腋板提高了节点的初始刚度和承载力,钢管梁的弹塑性性能得到了充分发挥,不同轴压比下均出现了塑性铰,导致加腋节点各试件的最终破坏均是由钢管梁塑性变形过大出现局部屈曲引起;加劲腋板提高了节点的延性系数及往复变形次数,延长了变形时间,增大了节点的粘滞阻尼和耗能性性能,改善了节点的抗震性能;随轴压比增加,加腋节点塑性变形减小,脆性破坏特征增加,各耗能系数均相应降低。The cold-formed thin-walled square steel tube has been widely applied in post-seismic reconstruction area after the Wenchuan earthquake.As there are no detail design instructions about this kind of structure,a further study is demanded on the connection mode and mechanical properties of the beam-column connection in the tube structure.A tridimensional double connection points model was proposed according to the actual building structure.By using cycling loading test,two types of full-scale beam-column connections（8 specimens） under different axial compression ratios were studied,among which four connections are welded with haunch slabs,and the others are not.According to the comparison of the results,failure modes and hysteretic curves of connection with welded haunch were obtained.Moreover,main parameters for estimating seismic behavior of connection with welded haunch were studied,such as load-carrying capacity,ductility ratio,stiffness degeneration,and energy dissipation coefficient.Meanwhile,ANSYS nonlinear finite element models were used to analyze the seismic behavior of the connection,and the results were also compared with the experimental results.The research shows that： analytical results agree well with experimental results,and the theoretical analysis proves to be correct.The ultimate failure of connection with welded haunch is caused by the local buckling of beam,and the yield surface is almost all located at outside of connections.The connection with welded haunch can experience more cycling times of deformation,which has longer yield platform after yield,stronger cumulative energy dissipation capacity and better ductility.Those properties can make connection consume much energy in earthquake and meet much better the need of seismic design.

关 键 词：冷弯薄壁方钢管 加腋节点 抗震性能 往复荷载 不同轴压比 有限元分析 

分 类 号：TU392.2[建筑科学—结构工程]