箱形节点域连接的工字形柱钢框架抗震性能试验研究

Experimental study on seismic behavior of box strengthened joint region for steel frames with I-section column

为研究采用箱形节点域与工形柱连接的钢框架结构的抗震性能,对由工字形柱强轴与弱轴方向采用箱形节点域连接的2榀钢框架结构进行了低周反复加载试验。试验结果表明：强轴连接钢框架具有较高的承载能力及良好的滞回性能,破坏时梁端出现塑性铰;弱轴连接钢框架的承载力相对偏低,但具有优于强轴连接钢框架的变形能力,且在弹塑性变形阶段具有与强轴连接钢框架相近的耗能能力,破坏模式与强轴连接基本相同;两榀钢框架的位移延性系数在2-3之间;试验中两榀钢框架的节点域始终处于弹性工作阶段,均未发生屈服。这表明箱形节点域连接属于“强节点域”连接,达到了“强节点弱构件”的抗震要求。箱形节点域连接可以有效减小节点域的剪切变形,采用该连接进行工字形柱钢框架设计时,在抗震设计中可以忽略节点域剪切变形对层间位移的影响。

In order to study the seismic behavior of box strengthened joint region connection on steel frames with I-section columns, two steel frames connected respectively in I-section column strong axis and weak axis were tested under cyclic loading. The experimental results show that steel frame with box strengthened joint in strong axis has better bearing capacity and hysteretic behavior. When it fails, the plastic hinge occurs in the beam section away from the column surface. The bearing capacity of steel frame with box strengthened joint in weak axis of I-section column is lower. However, the deformation property of it is better than the former. Furthermore, the energy-dissipation during the stage of elasto-plastic and failure mode are similar to the former. The ductility factor of the frames is between 2.0 and 3. O. All panel zones of the two steel frames remain elastic state during the test process, which indicates that the box strengthened joint region connection belongs to the connection of ＇ strong joint region＇. At the same time, it could satisfy the seismic design principle of ＇ strong joint and weak members＇ and reduce the panel zone shear deformation efficiently. Preliminary conclusion is that panel zone shear deformations influencing on story drift should be neglected during the first stage of seismic design when it comes to connecting beam and column with box strengthened joint region.