柱长细比对方钢管混凝土框架延性影响的分析

Analysis of the effect of slenderness ratio on the ductility of CFRT frames

长细比是影响钢管混凝土框架结构延性的重要因素.为研究长细比对方钢管混凝土框架结构延性的影响,建立了方钢管混凝土框架结构的非线性有限元分析模型,通过与方钢管混凝土框架结构在反复荷载作用下试验所得的滞回曲线进行对比,发现该模型的计算结果较精确,可应用于方钢管混凝土框架的结构分析中.利用此模型对在低周反复荷载作用下柱长细比不同的方钢管混凝土框架结构进行了有限元分析,对比研究了其滞回曲线和位移延性系数,得出了随着柱长细比的增加,方钢管混凝土框架延性降低的结论.

Slenderness ratio is one of the most important factors that have great effect on the ductility of concrete-filled steel tubular frames. In order to study its effect on the ductility of concrete-filled rectangular tubular frame, a nonlinear finite element analysis model is proposed in this paper. Compared with the experimental hysteretic curve, the computational results are found to be highly accurate, which shows that this model proposed in the paper can be applied in structure analysis of concrete-filled rectangular tubular frames. Then the model is used in the finite element analysis of concrete-filled rectangular tubular frames with different slenderness ratios of columns under low-reversed cyclic loading. Comparing the computational hysteretic curves and displacement ductility ratios, it can be concluded that the ductility of CFRT frames reduces with the increasing of the slenderness ratios of CFRT columns.