钢框架梁端腋板加强节点抗震性能研究

RESEARCH ON THE SEISMIC BEHAVIOR OF REINFORCED JOINTS OF HAUNCHED BEAM ENDS USED IN STEEL FRAME

选取钢框架中柱节点,设计并制作了3个十字形非对称腋板加强型节点进行滞回性能试验研究和ANSYS有限元分析。研究结果表明:3个非对称腋板加强节点试验试件均出现明显的塑性铰,滞回曲线饱满,骨架曲线具有明显的弹性、弹塑性、塑性发展过程;有限元结果表明:低周往复荷载作用下节点等效黏滞阻尼系数随腋板高度增大而减小、随腋板长度增加而增大,且随梁水平夹角增大,等效黏滞阻尼系数变化规律为先增加后减小,腋板水平夹角为30°左右时等效黏滞阻尼系数最大,耗能能力最强,有限元计算与试验结果取得了较好一致性;非对称腋板与对称腋板加强型节点相比,两类节点的延性系数、耗能能力等抗震性能相差不大,对称腋板加强型节点塑性铰处的外移机制更有效,塑性变形更为充分。

The middle column joints of a steel frame was selected to conduct hysteretic behavior test and ANSYS finite element analysis through 3 designed and fabricated unsymmetric cross reinforced joints of haunched plates. The experiment results indicated that obvious plastic hinge appeared at the 3 specimens,the hysteretic curve was full,and the skeleton curve had obvious elasticity,elastic plastic and plastic development process. The Finite element results showed that the equivalent viscous damping coefficient of the joints decreased with increase of the haunched plate height,and increased with increase of the haunched plate length. In a certain range,the equivalent viscous damping coefficient increased firstly and then decreased with the increase of the horizontal angle between the haunched plate and the beam. When the angle between the horizontal haunched plates was about 30 the equivalent viscous damping coefficient reached the biggest and the energy dissipation capacity was the strongest. The finite element calculation results and experimental results were in relatively good accordance. Compared with unsymmetric joints,the ductility,energy dissipation capacity differs little from symmetric joints. The plastic hinge＇s out-shift mechanism of unsymmetric joint was more efficient and the plastic deformation was more completely.