中文摘要：

进行共计20根缀条为K形布置的四肢钢管混凝土格构柱偏压及轴压极限承载力试验,重点考察偏心率与长细比对钢管混凝土偏压构件受力性能的影响。试验结果表明,长细比对试件承载力有一定影响,偏心率对承载力影响明显,两者对承载力的影响接近独立,试件的斜缀条在试验过程中始终保持弹性状态,近载一侧钢管在试件进入非线性阶段后,泊松比明显增大,钢管开始发生套箍作用,远载一侧,套箍作用不明显,除个别短柱外,试件破坏均为整体失稳破坏。同时,采用半波正弦曲线模拟杆件的变形曲线,在考虑紧箍效应的钢管混凝土应力-应变关系和剪切变形影响的基础上,建立杆件中截面的平衡方程,提出钢管混凝土格构柱弹塑性极限承载力数值方法,该方法不仅适用于两端偏心相等的偏压构件,而且适用于两端偏心不等的偏压构件的弹塑性极限承载力的计算;理论分析结果与试验研究结果对比表明,提出的钢管混凝土格构柱弹塑性极限承载力计算方法具有相当高的精度。

英文摘要：

Tests are conducted for 20 four-tube CFST lattice columns with K-shape lacing bars to study the ultimate bearing capacity of the axial and the eccentric compression lattice columns,and the influence of eccentricity and slenderness ratio on the mechanical properties of eccentric compression concrete-filled steel tube.The results show that eccentricity affects significantly on the bearing capacity of the specimens and the slenderness ratio has some degree of influences as well,though the two are independent.During the experiment,the diagonal lacing bars of the specimens are in elastic state.When the specimens reach the nonlinear stage,Poisson＇s ratio of the near-load steel tube increases significantly and begin to reflect confinement effect distinctively.As for the far-load steel tube,the confinement effect is insignificant.All specimens undergo integral buckling except for some short columns.A numerical method is presented for calculation of the elastic and plastic ultimate load carrying capacities of concrete filled steel tubular（CFST） lattice columns using a half-wave sinusoid curve to simulate the deformation curve of bar members,on the basis of stress-strain relationship considering confinement effect and the effect of shear deformation.The equilibrium equation of bar middle section is also established.This method can be applied to eccentric compression members with the same or different eccentricities at both ends.