薄壁方钢管混凝土柱-空心钢管梁加腋节点抗震性能试验研究

以轴压比为主要考察参数,对4个1∶1足尺模型的薄壁方钢管混凝土柱-空心钢管梁加腋节点进行低周反复荷载试验。通过试验观察其受力过程和破坏形态,得到梁端荷载-位移滞回曲线和骨架曲线,并分析节点的刚度退化、延性和耗能能力。结果表明:加腋板增强了节点域刚度,避免了焊接区域板件的脆性断裂,节点破坏由梁的局部屈曲引起,塑性铰形成于梁上并远离节点区域,柱和节点域基本完好,较好地满足了"强柱弱梁,节点更强"的抗震设计要求;试件的滞回曲线较饱满,延性系数为2.00~2.70;随着位移幅值的增加,试件的耗能能力不断提高,耗能性能良好;试件的极限承载力、延性及耗能能力等随轴压比增大无明显变化。

EXPERIMENTAL RESEARCH ON SEISMIC BEHAVIOR OF HAUNCHED JOINTS BETWEEN CONCRETE-FILLED THIN-WALLED SQUARE STEEL TUBULAR COLUMNS AND HOLLOW STEEL TUBULAR BEAMS

Considering axial compression ratio as the main parameter,the tests on four full-scale models of joints between concrete-filled thin-walled square steel tubular columns and hollow steel tubular beams were carried out under low-cyclic reversed loading. The loading process and the failure modes were observed,and the beam-end load versus displacement hysteresis loops and skeleton curves were obtained. Based on the experimental results,the mechanical properties of the joints such as the stiffness degeneration,ductility,energy-dissipating capacity were analyzed. The research indicates that because of the haunched plate,the stiffness of joint area is strengthened and the brittle fracture of the plates in the welded area is avoided,the failure of joints is caused by the local buckling of beam,and the plastic hinge appears on the beam where is away from the connection. The columns and the core of joints are undamaged. The joints better meets the seismic design principles,including"strong column and weak beam,stronger nodes". The hysteresis loops are plump,and the displacement ductility coefficients are between 2. 00 and 2. 70. With the increase of displacement,the energy-dissipating capacity of joints has been continually improved. And the ultimate bearing capacity,the ductility,the energy-dissipating capacity of joints have no obvious change with the increase of the axial compression ratio.