中文摘要：

钢管混凝土中钢管的高厚比越大，用钢量越少越经济，但当高厚比超过一定限值后钢管仍不可避免地产生局部屈曲；因此研究钢管混凝土中钢管的屈曲性能对于薄壁钢管混凝土设计具有重要指导意义．本文对24根空钢管和钢管填充混凝土后钢管的力学性能进行试验研究，试件的宽厚比为50～125；同时采用有限元软件Abaqus分析了钢管混凝土中钢板的屈曲性能，数值分析结果和理论分析结果进行对比，两者吻合较好．结果表明：钢管填充混凝土后改变了钢管的屈曲模式，明显提高了钢管的屈曲承载力，承载力的提高幅度随截面宽厚比的增加而增大．

英文摘要：

It is very important for the design of composite columns to accurately evaluate the maximum depthto-thickness ratio for which local buckling can be ignored and to determine the actual bearing capacities of slender columns which are influenced by local instabilities. This paper studied the behavior of bare steel tube and steel tube filled with concrete subjected to axial load. A total of 24 specimens were tested. The main pa- rameter is breadth-to-thickness ratio, which varies from 50 to 125. Also, the finite element software Abaqus was applied to analyze the behavior of hollow steel tube filled with concrete, whose accuracy were validated by comparing with the corresponding experimental results. The results showed that the concrete in the steel tube can increase the buckling bearing capacity evidently with the increase of breadth-to-thickness ratio.