方钢管混凝土柱-H型钢梁全螺栓连接节点抗震试验及有限元分析

Seismic test and finite element analysis of bolted joints connecting concrete-filled square steel tubular column and H-type steel beam

分别按照中、美两国规范中不同的加载制度,对3根方钢管混凝土柱-H型钢梁全螺栓连接节点试件进行反复低周荷载试验.结果表明,此类节点的滞回曲线、骨架曲线与焊接节点相比具有明显的特征.由于隔板翼缘相对滑移,滞回曲线均出现水平段,呈"捏缩形状".对比试验结果也发现:在全螺栓连接节点的试验中,由于滑移段的存在,按照位移角控制的加载制度的试验数据更为完整,优于按"两阶段"控制的加载制度.利用ABAQUS有限元软件,对反复低周荷载作用下方钢管混凝土与钢梁全螺栓连接节点的受力性能进行计算与分析,验证了试验结果的准确性,并通过刚度退化、延性指标及总承载力退化系数对节点抗震性能进行了分析.同时也提出了因存在隔板翼缘相对滑移,在评判过程中对这些指标加以修正的建议.

Three concrete-filled square steel tubular column and H-type steel beam for twosided all-bolted connections were fabricated according to the specifications of two countries,China and America.Repeated low cyclic loading tests were conducted on different loading systems.The results showed that the hysteretic loop curves and skeleton curves of the welded joint had obvious characteristics because of the relative slip in the clapboard flange,and the hysteretic loop curve in the horizontal section showed a pinch shrink shape.The test results indicated that the loading system controlled by the displacement angle was more complete and better than the loading system controlled by "two stages" owing to the existence of the slip section in tests on all the bolted joints.At the same time,using the finite element software,ABAQUS,for repeated low cyclic loads on the steel beam and concrete-filled steel tube,the stress performance of the bolt connection node was calculated and analysed.These results verified the accuracy of the test results.Further,the stiffness degradation,ductility performance,and overall strength degradation coefficient,of the seismic performance of the nodes were analysed.In addition,because of the existence of the relative slip in the plate flange,a revised evaluation of these indicators was proposed.