弯矩分布图形对钢管砼无侧移柱承载能力的影响

本文报导了27根两端弯矩不相等的无侧移钢管砼框架柱的试验结果。试验的主要参数为长细比、偏心率和较小端弯矩与较大端弯矩的比值β(=M_1/M_2)。试验结果表明,除了长细比和偏心率对试件承载能力有显著的影响外,端弯矩比对承载能力也有显著的影响。对于端弯矩不相等的非标准单元柱,其承载能力折减系数随长细比和偏心率而变化的规律与端弯矩相等的标准单元柱相似。文中根据这一规律,采用了一个等效长度系数k=0.5+0.3β+0.2β~2,将非标准单元柱转化为标准单元柱,应用“双系数乘积”公式计算其承载能力。经用本文和文献上的试验结果对建议的方法进行校核,实测值与计算值符合良好。

Influence of Moment Distribution Diagram on Load-Carrying Capacity of Concrete-Filled Steel Tubular Columns

This paper presents the test results of 27 concrete-filled steel tubular columns with pin ends and unequal end moments. The main experimental parameters are the slenderness ratio, eccentricity ratio, and the ratio of small to large end moments.Test results show that not only the slenderness ratio and eccentricity ratio affect the load-carrying capacity of columns,but also the end moments as well. The regularities of load-carrying capacity reduc lion factor vary with both slenderness ratio and the eccentricity ratio for non-standard columns (with unequal end moments) and are similar to those for standard ones( with equal end moments). According to this similarity, an equivalent column length coefficient, k = 0.5 + 0.3β + + 0.2β2, is introduced to transform the non-standard columns to standard ones. The proposed formulas are in good agreement with the authors' test results as well as those available in literature.