蜂窝轻钢门式刚架抗震性能试验研究

Experimental study on seismic performance of the castellated portal frame of light-weight steel

为了研究蜂窝轻钢门式刚架的抗震性能,对该类新型结构进行了低周反复荷载试验研究。设计两个蜂窝轻钢门式刚架试件进行试验,考虑了开孔形式、开孔率和节点域加劲肋三种参数对结构性能的影响。通过试验得到该类结构的破坏形态、荷载-位移曲线以及承载力等重要数据,分析结构的耗能能力、延性、刚度退化等结构性能与变化参数的关系。试验研究表明:蜂窝轻钢门式刚架在加载远端节点附近梁、柱上的蜂窝孔处形成塑性铰而发生破坏,具有良好的延性性能;蜂窝轻钢门式刚架的耗能能力小于普通门式刚架,且圆形开孔形式的蜂窝轻钢门式刚架的抗震性能比六边形开孔形式的好;随着蜂窝钢构件腹板开孔率的增大,结构的刚度和极限承载力有所降低;节点域受力较小,设计时只需按常规的节点处理即可,节点域无需设置加劲肋。研究结果可为蜂窝轻钢门式刚架的进一步研究和推广应用提供参考。

In order to study the seismic performance of the castellated portal frame of light-weight steel, the low cyclic reversed loading experiment was performed for this new structure type. Two specimens were designed and three influential parameters were considered including the opening forms, the opening ratio and stiffener in the joint region. The failure mode, the load-displacement curve and the bearing capacity were obtained from the test, and the relationship of the structural performance such as the energy dissipation capacity, the ductility and stiffness degradation with the variable parameters were studied. The results of study show that the castellated portal frame of light-weight steel is destructed by loading the castellated holes around the beam and column near the distal joints to form the plastic hinge, which presents excellent ductility. The energy dissipation capacity of the castellated portal frame of light-weight steel is less than that of the hexagon form portal frame, but the seismic performance of the castellated portal frame of light-weight steel with circle opening forms is better than that the hexagon from portal frame. The stiffness and the limit bearing capacity decrease when the web opening ratio of structure increases. Due to weak stress in the joint region, the stiffener should not be considered in the design of joints and joints could be designed according to the common joints. The results can provide reference for further research and application of the castellated portal frame of light-weight steel.