异形钢管混凝土短柱轴压力学性能研究

利用有限元分析软件ABAQUS建立等截面周长的三角形、扇形、D形、1/4圆形、1/2圆形5种异形截面钢管混凝土短柱轴压力学性能分析的有限元计算模型,对比圆形截面进行6组试验,有限元计算与试验所得的荷载-应变全过程曲线及短柱破坏形态吻合较好。在此基础上,对荷载-应变关系全过程中钢管与混凝土的相互作用进行分析,最后对截面形式、钢管壁厚(t)、钢管屈服强度(fy)、混凝土抗压强度(fcu)等几种影响异形钢管混凝土短柱承载力和变形的因素进行比较。结果表明:异形钢管混凝土短柱在1/2柱高处发生向外鼓曲破坏,截面形式、钢管壁厚、混凝土抗压强度等参数对其力学性能影响显著,钢管屈服强度对其力学性能影响不明显。

BEHAVIOUR OF SPECIAL-SHAPED CONCRETE-FILLED STEEL TUBULAR STUB COLUMNS UNDER AXIAL COMPRESSION

The finite element analysis( FEA) models for 5 special-shaped( triangular section,fan-section,Dsection,1 /4 circular section and semicircular section) concrete-filled steel tubular stub columns with the same perimeter of cross-section under axial compression are developed using ABAQUS software and the corresponding 6 group tests are conducted for comparison. The predicted load versus strain relationship curves and failure modes are in good agreement with the measured results. The FEA models are then used to analyze the interaction between the concrete and the steel tube during the whole loading process. And then,the main parameters influencing the bearing capacity and deformation such as section shape,steel tube wall thickness,steel tube yield strength,concrete compression strength are investigated. The results show the typical failure modes of these stub columns were the outward bulge at about mid-height,the section shape,the steel tube wall thickness and the concrete compression strength have obvious effects on their mechanical behavior,while the steel tube yield strength has slight effect on their mechanical behavior.