仿古建筑圆钢管柱-工字钢截面双梁节点抗剪承载力研究

Research on shear capacity of circle tubular steel column-double I-shaped section beam joints in imitated ancient building

为了研究仿古建筑圆钢管柱-工字钢截面双梁节点的抗震性能以及轴压比和节点约束效应对节点核心区抗剪承载力的影响,对4个全焊双梁-柱节点进行了水平低周反复加载试验。将节点域分为上、中、下3个小核心区,通过观测试件在侧向力作用下的破坏形态,研究双梁-柱节点的受力机理,得到节点域下核心区的剪力-剪切变形滞回曲线。从试验的滞回曲线可以看出,节点下核心区最先屈服且下核心区剪切角最大,上核心区次之,剪切变形发展均较为充分。试验结果表明,仿古建筑圆钢管柱-工字钢截面双梁节点破坏形式主要为沿节点下核心区对角线的剪切破坏。根据试验和理论分析结果,提出一种考虑轴压比和约束效应影响的双梁-柱节点的抗剪承载力计算公式。

In order to study the seismic behavior of circle tubular steel column-double I-shaped section beam joints in imitated ancient building considering the effect of axial compression ratio and restraint on shear capacity of the panel zone. The low-cyclic reversed loading test was carried out on four models of all-welded double beam-column joints. The panel zone is divided into three core areas as the upper,middle and lowers. According to the failure pattern of the specimens under the action of lateral forces,the mechanical performance and seismic behavior of the double beam-column joints were studied,the hysteretic loops of load versus strain in lower panel zone were obtained. It indicates that the first yield core area and maximum shear angle are both in the lower panel zone,the next is the upper zone and the shear deformation is mostly sufficient. It is shown that the failure was mainly occurred in lower panel zone,and it was along the diagonal. Based on the experimental and theoretical results,the calculating formula of shear capacity of double beam-column joints considering the effect of restraint and axial compression ratio is derived.