仿古建筑钢结构单梁-柱和双梁-柱节点动力加载试验研究

Dynamic experimental study on the single beam-column joints and double beams-column joints in steel archaized buildings

为研究仿古建筑钢结构节点在地震作用下的破坏模式和抗震性能,依据古建筑的形制和仿古建筑工程实例设计制作了1个单梁-柱节点试件和1个双梁-柱节点试件,并通过控制柱端位移和正弦波加载频率对试件进行了动力加载试验。观察了节点的破坏过程,对其滞回特性、延性、耗能能力、强度和刚度退化规律进行了分析。结果表明:节点梁端塑性铰区在加载过程中变形显著,试件破坏始于其梁端塑性铰区上、下翼缘的母材撕裂;试件滞回曲线呈梭形且较为饱满;试件破坏时的等效黏滞阻尼系数均在0.2以上,表明两类试件均具有良好的耗能性能,但双梁-柱节点的刚度、承载力要明显大于单梁-柱节点。单梁-柱节点和双梁-柱节点的延性系数分别为1.81和1.92,试件在动力加载过程中的变形发展较快,但延性不高,强度和刚度退化速度较快。

In order to study the failure modes and seismic behaviors of the joints in steel archaized buildings under earthquake action,a single beam-column joint and a double beams-column joint were fabricated according to the architectural form of ancient buildings and engineering instances of archaized building,and the dynamic loading test was designed by controlling the displacement of the column top and loading frequencies of sine waves.The failure process of the specimens was observed.The hysteretic characteristics,ductility,energy dissipation capacity,strength and stiffness degradation of the specimens were analyzed.Results show that obvious deformation occurs at the plastic hinge region near the beam root in the loading process,and the failure of the specimens is due to the fractures of the base material of the upper and lower flange.The hysteresis curves of the specimens are shuttle-shaped and plump.The equivalent viscous damping coefficient is larger than 0.2 when they are destroyed.It is also shown that two kinds of specimens have great energy dissipation capacity,whereas the stiffness,bearing capacity and energy dissipation capacity of the double beams-column joint are significantly better than that of the single beam-column joint.The ductility coefficients of the single beam-column joint and double beams-column joint are 1.81 and 1.92,respectively.The deformation of the specimens is fast,and the ductility is low under dynamic loading.The strength and stiffness degradation are also degenerated quickly.