钢管填充混凝土后屈曲承载力分析

为了研究钢管填充混凝土后钢管的力学性能,同时分析钢板的初始几何缺陷、残余应力及钢板屈曲后强度对填充混凝土后钢管的影响,采用大型有限元分析软件建立分析模型,并通过理论分析结果和实验结果的对比验证理论分析的正确性,在此基础上进行大量分析.研究结果表明:钢管混凝土中钢管的相对宽厚比≤50时,钢板在达到极限承载力之前没有屈曲现象产生;当相对宽厚比>50后,钢板会出现局部屈曲从而降低板件的承载力.钢板的初始几何缺陷和残余应力在一定程度上降低了大宽厚比下钢板的屈曲承载力,钢板屈曲后强度的存在明显提高了大宽厚比下钢板的屈曲承载力.通过分析给出了大宽厚比下钢管混凝土中钢板的承载力简化计算公式,可用于具体工程设计.

Research on the buckling bearing capacity of square steel tube filled with concrete

The finite element method is used to analyze the behavior of square steel tube filled with concrete. The accuracy of theoretical results validated against experimental results. Then based on the finite element method, the influence of initial deformation, the residual stress and the post-buckling behavior on the behavior of steel tube in composite columns are analyzed. When the relative width-to-thickness ratio is little than 50, the local buckling has no evident influence on the bearing capacity. While the relative width-to-thickness ratio is over 50, the local buckling will result in the decrease of bearing capacity of steel tube in square composite columns. For steel tube with large width-to-thickness ratio, the initial deformation and the residual stress will result in the decrease of bearing capacity, and the post-buckling behavior will increase the bearing capacity evidently. At last, the simplified formula of calculating bearing capacity of steel tube with higher width-to-thickness ratio is given, which can be used in the design.