T形钢管混凝土单向偏压长柱力学性能分析

Analysis of Behavior of Concrete-filled T-shaped Steel Tube Tall Column Subjected to Uniaxial Eccentric Load

采用普通T形钢管混凝土柱的核心混凝土等效单轴本构关系,利用纤维模型程序对T形钢管混凝土单向压弯长柱的力学性能进行分析,讨论了混凝土抗压强度、钢材屈服强度、管壁宽厚比、截面肢宽厚比、加载角度、长细比和轴压比等参数对构件偏压稳定承载力的影响.研究表明:混凝土工作承担系数、加载角度和长细比对正则化的轴力与弯矩相关曲线的形状有重要影响;基于大量数值结果回归分析,提出了T形钢管混凝土柱单向压弯承载力的简化计算方法,简化方法计算结果与纤维模型分析结果、试验结果吻合良好,简化方法可为工程设计提供参考.

In this paper,based on the equivalent uniaxial stress-strain relationship for concrete-filled T-shaped steel tube（CFTST）columns without stiffening measures,a fiber element model computing program was proposed for investigating the behavior of concrete-filled T-shaped steel tube slender columns,and the effects of different parameters on the behavior of CFTST columns under uniaxial eccentric load were investigated.The parameters in the analysis included the compressive strength of concrete,the yield strength of steel,the depth to thickness ratio of steel plate,the cross sectional depth to width ratio,the angle of the load,the slenderness ratio,and the axial load ratio.The results of theoretical analysis indicated that the normalized interaction curve of axial load versus bending moment was obviously influenced by the load ratio carried by core concrete,the load angle and the slenderness ratio. Based on the parametric analysis and regression analysis of a good many of numerical results,the simplified calculation methods were proposed to predict the load-carrying capacities of CFTST columns under uniaxial eccentric load.Good agreements between the values predicted by the simplified calculation methods,the fiber element model computing program and the experimental results were achieved,and the simplified calculation methods can be referred for practical engineering design.