钢结构仿古建筑带斗栱檐柱抗震性能试验研究及有限元分析

为研究矩形钢管柱长细比和轴压比对仿古建筑带斗栱檐柱抗震性能的影响，现对4个缩 尺比例为1∶1.5钢结构带斗栱檐柱进行了低周反复荷载试验，得到了各试件的滞回特性、刚度 和强度退化、位移延性及耗能性能，分析了檐柱的破坏形态和连接区应变分布。由试验研究结 果可知，试件破坏主要是由栌斗自身焊缝开裂、矩形钢管柱两侧根部翼缘与腹板连接处焊缝开 裂及翼缘与水平加劲环连接处热影响区母材拉裂造成的；试件滞回曲线饱满，连接区栌斗和矩 形钢管柱根部塑性变形充分；刚度和强度退化小，破坏时试件的位移延性系数及等效黏滞阻尼 系数均较高，表现了优越的变形及耗能性能。在试验基础上，采用ABAQUS有限元软件建立试件 三维模型，进行了轴压比、长细比等参数对其力学性能影响的参数分析。试验及数值模拟结果 表明：随轴压比增大，试件的弹性刚度变化不大，但延性均有不同程度的降低；增大长细比， 试件的延性提高，但水平承载力降低。

Experimental study and numerical analysis on seismic behavior of steel eave columns with Dougong in imitated ancient building

Four specimens of steel eave columns with Dougong in 1/1.5 scale were tested under low-cyclic reversed loading in order to investigate the effect of the slenderness ratio and the axial compression ratio of square steel tubular columns on the seismic performance of the joints. The hysteretic characteristics, degradations of rigidity and strength, ductility and dissipation capacity of the specimens were obtained. The failure modes and strain distribution in connection area were analyzed. The results indicate that the failures of eave columns with Dougong are mainly caused by weld fracture of Ludou and by the weld fracture at the connection between the two-side bottom flanges of the square steel tubular columns and the web, tension fracture of base material in the heat-affected zone of the columns. The hysteretic loops of the columns are plump. As the columns failed, both the ductility factor of the story drift and the equivalent viscous damping coefficient were large in magnitude, indicating that the columns have good deformation capacity and energy-dissipation capacity. The finite element program ABAQUS was used to generate 3D model in which the axial compression ratio and slenderness ratios were considered as analytical parameters. The experiment and numerical simulation results show that with the increase of axial compression ratio, the elastic rigidities of the specimens change insignificantly, whereas the ductility of the specimens may decrease to some extent. With the increase of slenderness ratio, the ductility of the specimens may increase, whereas their horizontal load-bearing capacities may decrease.