【摘要】 为研究蜂窝式钢框架梁柱节点的抗震性能,进行6榀框架边节点的低周反复荷载试验。当轴压比u=0.25和扩张比K=1.5时,在考虑梁上第一个开孔位置与其腹板高度之比d/ht和柱上第一个开孔位置与其腹板高度之比e/hc等控制参数的影响下,对其节点的受力过程、破坏模式、滞回曲线、骨架曲线、延性性能等因素进行研究与分析。研究表明:焊接质量是防止节点脆性破坏的首要保证。明显的焊接缺陷容易导致裂缝过早扩展,从而降低节点延性和耗能能力;与原型钢相比,梁柱腹板开孔扩高后,节点受弯承载力和转动刚度均有较大程度提高,梁端荷载-位移关系的滞回曲线饱满、稳定,刚度退化不明显,具有较好的耗能能力;扩张比一定的情况下,d/ht对节点抗震性能的影响要比e/hc显著,并且控制d/ht可以有效地将塑性铰外移到距节点域较远的梁截面上,大大缓解节点处的高三轴应力状态,降低连接焊缝发生脆性破坏的可能性,改善节点延性性能。更多还原

【Abstract】 Six edge connections of cellular steel frames(CSF) were tested under low-cyclic reversed loading in order to study the seismic behavior of welded beam-column connection of CSF.The effects of the parameters such as d/ht(ratio of the first opening position on the beam and height of beam web) and e/hc(ratio of the first opening position on the column and height of column web) were considered.The loading process,failure mode,hysteretic loop,skeleton curve,ductility and stiffness degradation of the connections of CSF were analyzed under axial compression ratio u=0.25 and outspread ratio K=1.5.It is indicated that welding quality is the primary assurance to prevent brittle failure of the connections.Welding flaws lead to early crack propagation,which can reduce the ductility and energy dissipation capacity of the connections.Comparing with the original connection without holes on beam-column web,the moment resistance capacity and rotational stiffness of the connections were improved after hole-opening and outspreading of beam-column web.Hysteretic loops of the load-displacement curves were stable and plump.No obvious stiffness degradation was observed.It is demonstrated that the connections of CSF had good energy dissipation capacity.When outspread ratio remains constant,the seismic behavior is influenced by d/ht more significantly than e/hc.Controlling d/ht can effectively change the plastic hinge to the beam section far away from the connection domain.In this way,the triaxial stress state close to the connection zone can be greatly alleviated,possibility of brittle damage of the welding is dramatically reduced,and the ductility performance of the connection is greatly improved.更多还原