仿古建筑矩形与圆形钢管柱连接抗震性能试验研究

为研究仿古建筑中矩形与圆形截面钢管柱连接的破坏形态和抗震性能，设计制作了4个缩尺比例为1∶1.5的矩形与圆形截面钢管柱连接模型，通过施加一定轴压比的竖向荷载和低周往复水平荷载，对柱连接模型进行加载破坏试验。观察了试件的受力过程及破坏形态，得到了柱端水平荷载-位移滞回曲线和骨架曲线。分析了长细比、轴压比对试件的破坏模式、滞回性能、刚度、承载力、延性和耗能能力的影响。结果表明：矩形与圆形截面钢管柱连接的破坏形态主要是矩形截面钢管柱翼缘根部周围焊缝开裂；滞回曲线饱满，刚度退化慢，承载力高，破坏时试件的位移延性系数介于4.17～4.97之间，等效黏滞阻尼系数介于0.445～0.537之间，具有很好的耗能能力及抗震性能。在试验研究的基础上，利用ABAQUS软件对该类连接构件进行了非线性分析，研究了轴压比、材料屈服强度、矩形钢管板件宽厚比等参数对其力学性能的影响，结果表明：提高轴压比和材料屈服强度，可提高连接构件的水平承载力，但延性降低；随着矩形钢管板件宽厚比的提高，连接构件的延性提高，但承载力有所降低。

Experimental study on seismic performances of connectionsbetween rectanglar steel pipe column and circular steel pipe column in imitated ancient building

In order to study the failure modes and seismic behavior of the connections between the rectanglar steel pipe column and circular steel pipe column in imitated ancient building, four specimens in 1∶1.5 scale of the prototype model were designed and manufactured. The destruction tests on the specimens were carried out under constant vertical load and low cyclic reversed load. The loading process and failure patterns were observed. The load-displacement hysteretic loops and skeleton curves were obtained. The influences of slenderness ratio and axial compression ratio on the failure pattern, hysteretic performance, stiffness, bearing capacity, ductility and energy dissipation capacity were analyzed. Test results show that connections damage at the welds near the root of the flange of the rectanglar steel pipe column. The hysteretic loops of the connections are in plump-shape. The connections have insignificant stiffness degradation and high bearing capacity. As the connections fail, the ductility factor of the story drift is between 4.17 and 4.97, and the equivalent viscous damping coefficient is about 0.445 to 0.537, showing excellent energy dissipation capacity and seismic behavior. Based on the experimental research, finite element analysis software ABAQUS was used to simulate the properties of specimens. The axial compression ratio, yield strength of steel, width-thickness ratio of square steel tube were taken as analytical parameters. The numerical simulation analysis results indicate that with the increment of the axial compression ratio and the yield strength of steel, the horizontal load-bearing capacity is improved, but the ductility of the member decreases. With the increment of width-thickness ratio of square steel tube, the ductility of the member is improved, but the horizontal load-bearing capacity decreases.