圆钢管混凝土轴压短柱受力机理影响因素分析

根据钢管混凝土轴压短柱弹塑性全过程分析理论,在试验验证的基础上,对钢管混凝土轴压短柱受力机理进行数值仿真,分析了钢管混凝土加载过程中各内力随纵向应变的变化情况,探讨了含钢率、钢材屈服强度和混凝土强度对钢管混凝土力学性能的影响。研究结果表明:钢管混凝土在受荷过程中,核心混凝土由于受到钢管的约束其纵向应力有较大提高,延性得到显著提高,钢管为混凝土提供径向约束,但其纵向应力大幅度降低;在其他条件相同的情况下,含钢率和钢材屈服强度越高,则钢管混凝土轴压短柱套箍作用越强,承载力越高,延性越好;而混凝土强度越高,则试件套箍作用越弱,延性越差,但承载力越高。

Parameters analysis of the behavior of concrete filled circular steel tubular stub columns

According to the elasto-plastic analysis theory for concrete filled tubular steel(CFTS) stub columns with circular section,which was verified by the test results,the behavior of the columns was simulated when loaded to failure,the axial stress-axial stain relations of steel tube,the perimeter stress-strain relations of steel tube and the axial stress-axial stain relations of concrete core were analyzed and the influences of the significant parameters,such as steel ratio,yield strength of steel and strength of concrete on the mechanical behavior of the columns were discussed.The results indicate that the axial stress of concrete core increases greatly and the ductility is improved when steel tube is confined.At the same time,the axial stress of steel tube decreases rapidly for confinement effect.When other parameters are the same,with the steel ratio and the yield strength of steel increasing,the confinement effect of columns is strengthened,and the ultimate strength and the ductility of columns grow.As the strength of concrete increases,confinement effect and the ductility of column are weakened but the ultimate strength of columns grows.