圆钢管混凝土柱在轴心受压下的理论解

将圆钢管混凝土视为统一材料（复合材料）,利用处于平面应变状态下的平衡方程,推导出严格满足应力、应变边界条件下的理论解.该理论解可以定量分析钢管混凝土柱的应力与应变状态,及其相应的有效模量（又称组合模量）和极限强度.根据理论解,套箍效应和极限强度不但与钢管、核心混凝土的泊松比有关,还与其弹性模量、组合材料的面积率有关.并通过实例将理论解和试验数据进行了对比,结果非常吻合.

THEORETICAL SOLUTION OF THE CONCRETE-FILLED STEEL TUBE COLUMN SUBJECTED TO AXIAL COMPRESSION

Taking concrete-filled circular steel tube （CFST） as a kind of composite material, and using the equilibrium equation of the plane strain state ,it was derived the theoretical solution that could meet strictly the boundary conditions of the stress and strain. The theoretical solution could be used to do quantitative analysis of the CFST stress and strain, the effective modulus （also known as the combined modulus） and the ultimate strength. According to the theoretical solution, the hooping effect and the ultimate bearing strength were not only related to Poisson ratio of the steel and concrete, their elastic modulus, but also related to the area rate of its composite material. Through examples theoretical and experimental data were compared, the results agreed very well.