设置直肋方形薄壁钢管混凝土长柱优化设计

目的探索设置直肋方形薄壁钢管混凝土长柱的增强效果,并优化设计其相关参数.方法通过分析9个无肋、单向和双向设置直肋方形薄壁钢管混凝土长柱偏压和轴压的试验结果,用正交试验设计和多元回归分析评价了加载初始偏心距、设置直肋集合长度对长柱极限承载力的影响.结果设直肋薄壁钢管混凝土长柱能达到较高的极限承载力,与无肋的普通钢管混凝土试件相比,偏心距70 mm试件的极限承载力提高了18.7%,偏心距40 mm试件提高了18.4%,轴压试件提高了21.1%.结论正交设计和多元回归分析证明设直肋能显著改善薄壁钢管混凝土的承载力,显示了优异的结构特征.

Optimal Designs of Square Concrete Filled Thin-walled Steel Tube Long Columns with Straight Ribs

According to the experimental results of nine tests of square concrete filled thin-walled steel tube(CFTST) long columns with or without straight ribs,the influence of the loading eccentricity and the width of straight ribs are analyzed by the method of optimal design.The study shows that the mechanical capability of CFTST long columns with straight ribs can be improved effectively.Compared with those with straight ribs,the limit capability of those with(70?mm) eccentricity increases by 18.7%,that of those with 40mm-eccentricity by 18.4%,that of those with axial pressure by 21.1%,which proves that CFTST long columns with straight ribs can largely improve the loading capacity and are therefore superior in structure and turn out to be an optimal design.