中文摘要：

应用弹性力学理论和钢管混凝土柱协同工作条件,推导出了钢管混凝土柱组合轴压弹性模量和轴向压力分配的理论计算公式。公式表明,组合弹性模量不但与混凝土泊松比、单向轴压弹性模量和混凝土柱截面直径有关,而且和钢管泊松比、单向轴压弹性模量以及含钢率有关。作为计算例,用MATLAB编程考察了混凝土强度等级和含钢率对混凝土轴向压力分配系数、钢管混凝土柱组合弹性模量的影响。研究结果表明：混凝土轴向压力分配系数随着含钢率增大而递减,随混凝土强度等级提高而增大;与不考虑紧箍效应相比,考虑紧箍效应的情况下,核心混凝土的轴向压力有一部分传递给了钢管;含钢率越大,组合轴压弹性模量越大;混凝土强度等级越高,组合轴压弹性模量越大;用本文理论计算公式算得的组合弹性模量与按照统一理论所得的结果相近。由于刚管混凝土柱外钢管约束,核心混凝土的轴压刚度提高了至少20%。

英文摘要：

In this paper formulae to evaluate the composite elastic modulus and the axial compressive distribution of concrete filled steel tubular（CFST） columns were derived by combining elastic mechanics and working conditions of concrete-filled steel tubular columns. It showed that the elastic modulus relates to not only the Poisson ratio, section diameter and elastic modulus of the concrete, but also the Poisson ratio, wall thickness and modulus of the steel tube. As an application example, effects of concrete strength grade and steel ratio on the composite elastic modulus of CFST and its axial compressive distribution were discussed through MATLAB. Results indicated that, the concrete compression distribution coefficient decreased with the increase of the steel ratio but increased with increasing concrete strength grade; part of axial compression in the core concrete was transferred to the outer steel tube for the confined CFST compared to the unconfined CFST; the greater the steel ratio and the concrete strength grade, the larger the composite elastic modulus of CFST. The present theoretical results of the composite elastic modulus were in good agreement with those calculated by the unified theory.