L形钢管混凝土轴压短柱力学性能研究

Study on Behavior of L-Shaped Concrete-Filled Steel Tube Stubs Subjected to Axial-Compression

本文进行了四根有加劲和二根无加劲的L形钢管混凝土短柱轴压试验。对试件破坏过程及结果进行了较为详细的描述,在此基础上,考察了不同宽厚比和内部有无加劲肋对试件承载力和延性的影响。结果表明:L形钢管混凝土柱延续了钢管混凝土的特性,有良好的受力性能;当钢管宽厚比不大于60(即短肢柱)时,加劲肋虽然对L形钢管混凝土的承载力没有明显的贡献,但是可以有效地提高其延性;而当钢管宽厚比大于60(即长肢柱)时,加劲肋对L形钢管混凝土柱的承载力及延性均无明显影响。最后,在选择合理的钢材和核心混凝土本构关系基础上,采用大型通用有限元分析程序ABAQUS建立了轴压荷载下L钢管混凝土柱的三维非线性有限元分析模型,分析了构件的荷载-变形关系,计算表明,计算曲线与试验曲线吻合良好。

Based on axially compressive tests of 4 L-shaped concrete filled steel tube stubs with rib and the other two without rib, the failure modes and test results of specimens, which were tested to investigate the effect of width-to-thickness, with or without rib and leg length on the ultimate strength and ductility of the column, were described in detail. Experimental results suggest that L-shaped concrete-filled steel tube stubs maintain the characteristics of the concretefilled steel tube which has excellent bearing capability. When the width-to thickness of steel tube is not larger than 60 （short leg column）, the rib＇s contribution to the bearing capability is not very remarkable but to the ductility of the column is very effective. However, when the width-to-thickness of the steel tube is larger than 60, the rib has obvious contribution to neither the bearing capability nor the ductility of the column. Based on the determination of steel stress-strain relation and core concrete stress-strain relation, the three dimensional nonlinear finite element analysis model of concrete-filled steel square tubular column bearing axial compressive load is established using large finite element software ABAQUS, and the member load-deformation relation is analyzed, and the simulated curves agree well with the experimental results.