圆钢管混凝土偏压柱全寿命周期力学性能研究

RESEARCH ON MECHANICAL PROPERTIES OF WHOLE LIFE CYCLE OF ECCENTRICALLY LOADED CFST COLUMNS

基于合理的材料本构关系,运用有限元软件ABAQUS分别建立考虑钢管初应力、混凝土脱空缺陷和长期荷载作用时钢管混凝土柱的数值分析模型。在模型验证的基础上,进行圆钢管混凝土偏压柱全寿命周期受力全过程分析,同时与一次加载的结果进行对比,最后对初应力系数、混凝土脱空率、长期荷载比、偏心率4个典型因素进行参数分析。结果表明:圆钢管混凝土偏压柱全寿命周期的极限承载力小于一次加载时的情况,其极限承载力所对应的挠度却比一次加载时大;组合柱全寿命周期的极限承载力随着偏心率的增大而降低明显,随着初应力系数、混凝土脱空率的增大而略有降低,而长期荷载比对其影响较小。

Based on the reasonable material constitutive relation,the paper used the finite element software ABAQUS to respectively establish the numerical analysis models of concrete filled steel tube column considering tubular initial stress,initial concrete imperfection and long-term loads. On the basis of the verified models,the whole process of loading behavior of eccentrically loaded circular CFST column was analyzed and compared with the results of complete loading. Finally,the parametric studies were conducted in terms of initial stress coefficient,ratio of concrete gap,the long-term load ratio and eccentricity. The results showed that the ultimate strength of eccentrically loaded circular CFST column considering the whole life cycle was less than the case of complete loading,the deflection corresponding to ultimate strength was larger than complete loading; the ultimate strength of the whole life cycle of eccentrically loaded composite column decreased obviously with the increase of eccentricity,with the increase of initial stress coefficient and the ratio of concrete gap slightly,while varied a little with long-term load ratio.