型钢混凝土约束柱耐火性能研究

Fire Performance Study of Steel Reinforced Concrete Restrained Columns

基于ABAQUS有限元软件,选取合理的材料本构模型,建立温度和荷载耦合作用下型钢混凝土约束柱有限元模型,有限元模型的计算值与已有试验结果吻合较好。利用上述模型考虑荷载比和荷载偏心率的影响,对不同轴向约束和转动约束作用下的型钢混凝土约束柱的耐火性能进行系统的参数分析。结果表明:轴向约束相当于竖向约束弹簧,在一定程度上分担柱顶竖向荷载,有利于提高柱的耐火极限;转动约束相当于转动约束弹簧,在一定程度上减小弯矩沿柱长的分布值,同时也阻止柱半高处的侧向变形;轴向约束作用或轴向约束和转动约束共同作用下,荷载比相同且小于或等于0.6时,柱的耐火极限随偏心率的增大而增大,偏心率相同时,柱的耐火极限随荷载比的增大而减小。

Based on ABAQUS finite element software,appropriate material constitutive model is selected,and the theoretical calculation model under the coupling effects between temperature and load is proposed. The results of finite element analysis models are in good agreement with the experimental results. Under different load ratio and eccentricity ratio,the model is used to analyze the fire-resistant performance of the steel reinforced concrete columns with different axial and rotational restraints. The results show： the axial restraints,which are similar to the vertical restraint springs,could share vertical load of capital to a certain extent,and could improve the fire resistance of columns; the rotational restraints,which are similar to the rotational restraint springs,could reduce the moment distribution along the column,and could also prevent lateral deformation at the middle of column; under axial restraints or axial and rotational restraints,if the load radio is less than or equal to 0. 6,the fire resistance of column increases with the increasing of eccentricity,and if eccentricity is the same,the fire resistance of column decreases with increasing of the load ratio.