横肋波纹钢板-钢管混凝土短柱轴压受力机理研究

Mechanism of concrete-filled horizontal corrugated steel tubular short columns subjected to axial compression

横肋波纹钢板-钢管混凝土柱(CFHCST)是由四角方钢管与侧壁波纹钢板焊接形成的多腔体与混凝土组合而成。为研究其受力机理及轴力分配规律,本文采用ABAQUS建立了CFHCST的分析模型,并基于得到的试验数据验证了该模型的准确性。在此基础上,从构件的荷载-纵向应变曲线、各钢材组分的应力-应变曲线发展规律及混凝土的纵向应力分布等多方面进行了分析,同时评价了不同参数对其承载力、延性及承载力提高系数的影响。研究结果表明:波纹钢板几乎不承担轴向荷载,构件承载力的大小主要由核心混凝土和方钢管混凝土决定;构件截面的强约束区主要集中在核心混凝土的截面核心处以及方钢管角部;波纹钢板表面受力不均匀,波峰与波中处钢材均表现为双向受拉,且波峰对混凝土的约束效果最好。在结合现有规范以及有限元参数分析结果的基础上,建立了CFHCST承载力计算公式。公式计算结果偏于安全,可为工程设计提供参考。

Concrete-filled horizontal corrugated steel tubular(CFHCST) is steel-concrete composite section member composed of horizontal corrugated steel and square steel tube. To investigate its axial compression mechanism and axial force distribution rule, the finite element modelling of CFHCST by using ABAQUS program and the accuracy of program is validated using previous experimental results. On this basis, the load-longitudinal strain curve of member, the stress-strain curve of each steel component and the longitudinal stress distribution of concrete are analyzed and the effect on bearing capacity, ductility and strength index by different parameters are discussed. The Study revealed, bearing capacity of the member is mainly determined by the core concrete and the square steel tube concrete because the axial load could not pass the corrugate steel;the strong constraint area of the member section is mainly concentrated in the core of the core concrete section and the corner of the square steel tube;the steel of crest and trough perform bidirectional tension owing to the uneven force on the surface of the corrugated steel plate and the confinement effect of the crest on core concrete is the best. On base of the existing code and the parameter analysis, the calculation formula of CFHCST bearing capacity is established. The calculation result of the formula is safe and can be used as reference for engineering design.