中文摘要：

通过试验研究与数值模拟的方法,确定微膨胀C50圆端形钢管混凝土的应力应变关系,并结合工程实例,用泊松比的变化来模拟核心混凝土的微膨胀效应,分析施工中圆端形钢管混凝土双肢柱在轴心受压和偏心受压两种情形下的受力性能.分析结果表明,在考虑混凝土泊松比变化情况下,极限承载力比不考虑混凝土泊松比变化时的计算值高;这种结构在轴心受压时,应力变化很小;在承受偏心荷载时,应力增幅较大,且能充分利用其结构形式上的特点.

英文摘要：

The stress-strain relationship of the round-ended concrete filled steel tubes（CFSTs）were considered with test study and numerical simulation;and based on an example of project,to simulate the microexpansive effect by making use of the variation of Poisson＇s ratio,the mechanical properties of the roundended CFST coupled column were analyzed with the stress monitoring and finite element methods in axial compression and eccentric compression.The results show that：With the variable concrete Poisson＇s ratio,comparatively,the bearing capacity analysis considering the variable concrete Poisson＇s ratio enables to enhance the design capacity;the stress of the structure changes little in axial compression,but increases largely while bearing eccentric loads;especially it can make full use of the characteristics of the form of this structure.