延性节点空间钢框架在低周反复荷载作用下的滞回性能研究

STUDY ON HYSTERETIC PERFORMANCE OF SPACE STEEL FRAME WITH DUCTILE JOINTS UNDER LOW CYCLIC LOADING

为研究延性节点在整体钢框架中的抗震机理及性能,设计了3个缩尺比例为1∶3的不同节点构造形式的空间钢框架计算模型,分别为圆弧削弱型节点钢框架RBF、直接扩翼型节点钢框架KYF和普通标准节点型钢框架OSF,并利用ANSYS有限元分析软件进行了拟静力加载分析,创新性地采用二层施加位移、一层同时施加力荷载的同步混合加载制度施加水平地震作用。分析结果表明:圆弧削弱型节点钢框架和直接扩翼型节点钢框架均能较好地实现塑性铰外移的设计目的,有效保护了梁柱连接节点处焊缝不发生脆性破坏,并能延缓柱脚处的塑性变形和破坏。与普通节点钢框架相比,延性节点钢框架滞回曲线饱满、延性好、耗能能力强。

To study the mechanism and performance of ductility joints of steel frame,it was designed three 1∶ 3 scale models of two-story single-span space steel frames with different joints,which were referred to as RBF,KYF,and OSF,and finite element software ANSYS was used to conducted quasi-static cyclic loading simulation, where horizontal seismic load was applied by the way of synchronization mixed loading,displacement was applied to second story and loading was applied to first story. The results showed that both the steel frames of the arc-type weaken joint and the arc-type expansion wing joint achieved the design purpose of relocating plastic hinge,effectively protected the beam-column connection joint welds against brittle failure and put off the occurrence of plastic deformation and damage at the column foot. In comparison with steel frame with standard joint,the hysteresis curve of ductility joint steel frame was plump,had better ductility and stronger energy dissipation capacity.