实、空心钢管混凝土抗扭承载力统一计算方法

A UNIFIED FORMULA FOR HOLLOW AND SOLID CONCRETE-FILLED STEEL TUBE COLUMNS UNDER TORSION

目前关于钢管混凝土抗扭承载力的计算方法已有一些,但大多是针对实心钢管混凝土。通过建立钢管混凝土构件在纯扭作用下的有限元模型,并对钢管混凝土的受扭性能进行数值参数分析,着重探讨空心率对钢管混凝土横截面受力分布和承载力的影响,基于极限平衡方法推导钢管混凝土在纯扭下的承载力计算式,最终给出实心和空心完全统一的抗扭承载力计算式,并收集相关试验数据对得到的计算式进行试验验证,通过试验对比,说明计算式的有效性,同时计算式物理意义明确,形式完全统一,较好地反映了实心和空心钢管混凝土构件工作性能的连续性。

Currently,there are some methods for calculating the torsional bearing capacity of concrete-filled steel tube（ CFST） columns. However,these methods were mostly used for solid concrete-filled steel tube（ S-CFST）. In this paper,the finite element model of concrete-filled steel tube columns under pure torsion was adopted to analyze the torsion behavior of the concrete-filled steel tube columns,and the influence of hollow ratio on the stress distribution of the cross section and the bearing capacity of CFST was investigated. Based on the elastic and plastic limit analysis,the bearing capacity formula of concrete-filled steel tube columns under pure torsion was deduced. Finally,a unified torsional bearing capacity formula for solid and hollow concrete-filled steel tube columns was proposed,which was verified by experimental data. One of the important features of the new formulas is that they provided a unified formula for both hollow and solid CFST columns that related the torsion capacity of a CFST column and a series of design parameters.