【摘要】 震害表明,高层建筑中轴压比较大的钢筋混凝土柱的变形能力较弱。为了提高大轴压比柱的变形能力,进而改善结构的抗震性能,采用钢管混凝土叠合柱是最有效的方法之一。本文首先通过截面分析,阐释了钢管混凝土叠合柱在高轴压比下提高柱子延性的机理。然后基于已有的钢管混凝土叠合柱试验,采用通用非线性有限元软件ABAQUS建立了钢管混凝土叠合柱的有限元模型。有限元分析结果与试验结果吻合良好,说明了有限元模型的合理性。在此基础上,分析了名义轴压比、套箍系数等参数对钢管混凝土叠合柱位移延性系数的影响,得到了影响外围钢筋混凝土与核心钢管混凝土之间轴力重分配和叠合柱延性的关键参数。通过回归分析,得到反映各关键参数影响的叠合柱位移延性系数的简化计算公式,在此基础上,计算得到了各抗震等级叠合柱位移延性系数的下限值,为叠合柱的延性估算和复核提供参考。更多还原

【Abstract】 From earthquake damages,it is shown that the deformability of reinforced concrete column in high-rise building is unsatisfactory when the axial compression ratio of the column is high.In order to improve the deformability of the reinforced concrete column with high axial compression ratio,and improve the seismic performance of the structure,the steel tube-reinforced concrete column is used as one of the most effective way.First,by section analysis,this article illustrates the mechanism of improving ductility of steel tube-reinforced concrete column with high axial compression ratio.Then based on the existing test of steel tube-reinforced concrete column,the finite element models of steel tube-reinforced concrete columns are established by nonlinear finite element software ABAQUS.The well agreements between the finite element analysis and experimental results indicate the rationality of the finite element model.On the basis,we get the key parameters for effecting axial force redistribution and ductility of composite column between peripheral reinforced concrete and core concrete filled steel tube by analyzing the influence of some parameters such as nominal axial compression ratio,confinement coefficient and stirrup characteristic value on the displacement ductility coefficient of steel tube-reinforced concrete column.The formula of displacement ductility coefficient of composite column which reflects the influence of key parameters by fitting of finiteelement data is proposed.The lower limit bound of seismic displacement ductility coefficient of composite column under different seismic rating is also suggested which can provide a reference for estimating and reviewing the ductility of composite column.更多还原