钢框架扩翼型节点抗震性能研究

Study on seismic behavior of widened beam flange connections of steel frame

基于4个梁端翼缘扩大型节点试件和1个传统节点试件的低周循环加载试验,对直接圆弧扩翼型节点和加侧板扩翼型节点2种钢框架扩翼型节点采用ANSYS软件进行了往复荷载作用下的节点性能有限元分析,研究了这2种不同型式的梁端扩翼节点的破坏形态、荷载-位移滞回曲线、骨架曲线、极限荷载、延性和耗能系数等抗震性能,其结果与试验结果吻合较好。研究结果表明,通过合理地设计扩翼截面,圆弧扩翼型节点和侧板扩翼型节点均能有效的将塑性铰移出焊缝热影响区,且较传统节点具有更强的承载力、延性和耗能能力,能满足我国现行抗震规范的要求。另外,圆弧扩翼型节点构造相对简单,扩翼处连接焊缝少,可避免焊接热影响区母材变脆而发生脆性撕裂,其抗震性能要优于梁端翼缘侧板加强型节点。

Based on the experiments of four widened beam flange connection specimens and one traditional joint specimen under low period cyclic loading,failure forms and seismic behavior of direct arc widened beam flange connections and welded side-plate connections were studied by ANSYS software,such as load-displacement hysteretic curve,skeleton curve,ultimate load,ductility and energy dissipation factor etc.The comparability between the results from the analyses and those from the experiments is satisfactory.Results of the research show that through properly designing the section of widened flange,the plastic hinge of beams can be effectively moved outward from welded connection area in both arc widened beam flange connections and welded side-plate connections,and the two kinds of widened flange beam connections have better ductility,bearing capacity and energy dissipation capacity than the traditional connection and may satisfy the demand from current Chinese seismic design code.In addition,because the arc widened beam flange connections have simpler conformation and fewer welds at the section of widened beam flange,which avoid brittle rapture due to the materials becoming brittle in the weld heat-affecting zone,they have better seismic property than the welded side-plate connections.