矩形钢管混凝土轴压柱的弹塑性局部屈曲模型

Elastic-plastic local buckling model of rectangular CFT columns under axial compression

假定载荷边为固端约束,非载荷边为弹性可转动约束,提出了轴压下矩形钢管混凝土柱弹塑性局部屈曲模型.利用全量理论推导得到钢管混凝土柱钢管弹塑性局部屈曲强度计算公式.该公式的计算结果与已有的试验结果比较,结果表明理论计算结果与试验结果相符.基于所提出矩形钢管混凝土柱弹塑性局部屈曲模型,研究了不同长宽比情况下钢管宽厚比对钢管弹塑性局部屈曲应力的影响.最后给出了不同截面长宽比情况下,保证矩形钢管屈服前不发生弹塑性屈曲的钢管宽厚比合理限值及各钢板的合理厚度比,供工程设计参考.

Assuming that the loaded edges of steel plates are clamped,while the unloaded edges are restrained against rotation,the elastic-plastic local buckling model of rectangular CFT columns was proposed.The formula for calculating elastic-plastic local buckling strength of steel plates in rectangular CFT columns were proposed using the deformation theory of plasticity.The calculated results by formula were compared with the experimental results,showing good agreement between the calculated results and the experimental results.Based on the proposed elastic-plastic local buckling model of rectangular CFT columns,the effects of width-to-wall thickness ratios on the elastic-plastic local buckling critical stress of the steel tube in the cases of different cross-sectional aspect ratios were investigated.Finally,the reasonable limitations for width-to-wall thickness ratios and the reasonable thickness ratios of the steel plates in the cases of different cross-sectional aspect ratios are suggested for engineering design,which can ensure that the elastic-plastic local buckling of the steel tube can not occur before the steel yield.