薄壁方钢管再生混凝土短柱屈曲承载力

Buckling Bearing Capacity of Recycled Concrete-filled Thin Walled Square Short Steel Tube

钢管再生混凝土结构是近年来发展起来的一种新型结构形式,薄壁方形钢管再生混凝土构件的钢管壁容易产生局部屈曲而使构件承载力降低,而目前的钢管再生混凝土承载力计算公式中均未考虑局部屈曲的影响。本文在考虑核心混凝土对钢管产生径向力作用并假定非载荷边为弹性约束的情况下,采用能量法对钢管进行屈曲性能分析,并推导出屈曲系数计算公式,再在此基础上采用有效宽度法来考虑薄壁方钢管发生局部屈曲对承载力的影响,从而提出薄壁方钢管再生混凝土轴压短柱承载力计算公式,并用试验数据验证其合理性,研究结果表明:弹性约束系数和钢管的横向力对屈曲系数有一定的影响,当构件截面宽厚比较大时,应当考虑钢管局部屈曲对承载力的降低。

Recycled concrete-filled steel tube is a new type of structure which has been developed in recent years. For recycled concrete-filled thin-walled square steel tube member, the steel tube wall is prone to local buckling and the bearing capacity of the member is reduced. But the effect of local buckling of the member is not considered in the calculation formula of bearing capacity. In this paper, it assumed that the steel plate is subjected to spring constrain at the unloading edge and the radial force of the core concrete is considered, the buckling behavior of steel tube is studied by using energy method and the calculation formula of buckling coefficient is derived. Based on the effective width method, the effect of local buckling on the bearing capacity of the thin-walled square steel tube is considered. The calculation formula for the bearing capacity of the recycled concrete-filled steel tube axial compression stub column is put forward, and the rationality of the formula is verified by the experimental data. The results show that the elastic constraint coefficient and the lateral force of the steel tube have a certain influence on the buckling coefficient. When the section width thickness is relatively large, the local buckling of the steel tube should be considered.