异形钢管混凝土轴压短柱的非线性分析

Behavior of L-Shaped Concrete-Filled Steel Tubular Columns Subjected to Axial-Compression

为深入了解L形钢管混凝土柱在轴压荷载作用下的力学性能,以试验为基础,参考常用的方钢管混凝土柱核心混凝土本构关系,提出采用等效约束效应系数■B来考虑L形钢管对混凝土的约束作用,利用有限元软件ABAQUS建模对L形钢管混凝土柱轴压时的力学性能进行了非线性分析,给出了有限元计算钢管和核心混凝土本构关系模型、钢管与混凝土间界面模型的确定方法,计算和分析了其荷载-变形关系曲线,计算结果与试验结果吻合较好。典型L形钢管混凝土轴压短荷载-变形关系曲线可以分为3个阶段:弹性阶段、弹塑性阶段和下降段,在此基础上研究了宽厚比、长宽比、钢管屈服强度和混凝土强度对L形钢管混凝土柱承载力提高系数的影响。

The mechanism of L-shaped concrete-filled steel tubular column subjected to axial-compression is studied based on experiment and the constitutive relations of the core concrete of concrete-filled steel square tubular column.A constitutive relationship of the core concrete confined by L-Shaped steel tube is put forward,with the restriction of steel tube to concrete as an equivalent confinable effect coefficient ξDB.Nonlinear finite element method analysis on L-shaped concrete-filled steel tubular column is carried out by using ABAQUS software.Determination methods for the constitutive models of steel and concrete,interface model between the steel tubes and the concrete are presented.The load-deformation relationships of L-Shaped concrete-filled steel tubular columns subjected to axial compression are analyzed,and the calculation results are in good agreement with experimental results.The typical load-deformation relationship curves of L-shaped concrete-filled steel tubular column subjected to axial-compression shown could be defined as following three stages： elastic,elastic-plastic and softening stage.Parametric analyses are conducted at the added coefficient of bearing capacity of L-shaped concrete-filled steel tubular column to investigate the influence of width-thickness ratio,length-width ratio,yield strength of steel tube and strength of the core concrete