内填木芯钢管混凝土短柱轴压性能有限元分析

Finite Element Analysis of Concrete-Filled Steel Tubular Short Columns with Timber Core Under Axial Compression

在钢管混凝土内部填充部分木芯能够在不大幅降低钢管混凝土柱承载力的情况下,有效减轻钢管混凝土柱的自重。采用ABAQUS有限元软件建立内填木芯钢管混凝土短柱实体模型,研究了不同含木率、木芯截面形状、钢管截面形式和钢管壁厚等参数对内填木芯钢管混凝土短柱轴压性能的影响。结果表明:一定范围内,内填木芯使得钢管混凝土短柱的承载力有所下降,但是柱的强重比却逐渐增大;木芯的截面形式对柱的承载力总体上影响较小。同时借鉴约束钢管的本构关系,提出内填木芯钢管混凝土轴压短柱承载力的简化计算式。采用建议计算式对内填木芯钢管混凝土轴压短柱进行承载力计算,计算结果与有限元模拟值、试验值吻合良好。

Partially replacing infilled concrete in concrete-infilled steel tubes(CFST)with timber cores can effectively reduce the mass of CFST columns without significant loss on the axial load-bearing capacity.Using ABAQUS finite element software,a model of concrete-filled steel tubular short column with timber core is built.The influences of timber core ratio,timber core section,steel pipe section and wall thickness on the axial compression performance of concrete-filled steel tubular short columns are studied.The results indicate that within a certain range,partially-infilled timber core can reduce the bearing capacity of concrete-timber-filled steel tubular short columns.However,the strength-to-weight ratio increased with the increase of timber core ratio.In general,the section form of timber core has little influence on the bearing capacity of columns.At the same time,based on the constitutive relationship of the constrained steel tube,a simplified formula for the calculation of the bearing capacity of CFST columns under compression is proposed.The proposed formula is used to calculate the bearing capacity of CFST columns under axial compression,and the calculated results have a good agreement with the finite element simulation results and test results.