套箍系数对圆台形钢管混凝土柱轴压性能影响的有限元分析

Finite element analysis of the influence of hoop coefficient on the axial compression performance of circular concrete filled steel tubular columns

为研究套箍系数对圆台形钢管混凝土柱轴压性能的影响,使用有限元软件ABAQUS对已有的3个圆台形钢管混凝土柱试件进行建模计算和验证,并以套箍系数和长径比为变化参数进行了13个试件的拓展分析,探讨了各影响因素对试件轴压性能的影响。结果表明:建立的有限元模型能精准地模拟圆台形钢管混凝土柱的轴压力学行为,荷载-位移曲线和破坏形态均呈现高度吻合;随着柱中套箍系数的增大,试件的极限承载力呈线性增大,套箍系数由0.1增大至0.4,极限承载力提高95%;随着柱中长径比的增大,试件由强度破坏过渡为失稳破坏,轴压刚度和极限承载力均有不同程度退化;提出的与套箍系数相关的极限承载力提高系数计算方法和与长径比相关的稳定系数计算方法具有较好的吻合度。

In order to study the influence of hoop coefficient on the axial compression performance of circular frustum con-crete-filled steel tubular column,three existing specimens of circular frustum concrete-filled steel tubular column are modeled,cal-culated and verified by using the finite element software ABAQUS.Taking the hoop coefficient and length diameter ratio as changing parameters,the expansion analysis of 13 specimens is carried out,and the influence of various influencing parameters on the axial compression performance of specimens is discussed.The results show that the finite element model can accurately simu-late the axial compressive mechanical behavior of circular concrete-filled steel tubular columns,and the load displacement curve is highly consistent with the failure mode.With the increase of hoop coefficient in the column,the ultimate bearing capacity of the specimen increases linearly,the hoop coefficient increases from 0.1 to 0.4,and the ultimate bearing capacity increases by 95%.With the increase of the length diameter ratio in the column,the strength failure of the specimen transits to instability failure,and the axial compression stiffness and ultimate bearing capacity degrade in varying degrees.The calculation method of ultimate bearing capacity improvement coefficient related to hoop coefficient and the calculation method of stability coefficient related to length di-ameter ratio are in good agreement.