钢管交叉斜杆计算长度系数研究

RESEARCH ON THE EFFECTIVE LENGTH COEFFICIENT OF CROSSED STEEL TUBES

对于交叉点为杆件中点的钢管交叉斜杆,规范中有其计算长度系数的计算方法,但是各种规范的计算结果差异较大。建立钢管交叉斜杆的有限元模型,对其计算长度系数进行研究,并与规范中的公式进行对比分析。结果表明,长细比对压杆的计算长度系数的影响很小,可以忽略不计;在一拉一压工况下,建议钢管交叉斜杆的计算长度系数采用GB 50017—2003《钢结构设计规范》中的另一杆不中断情况下的计算值;在同时受压工况下,建议钢管交叉斜杆的计算长度系数采用GB 50017—2003中的另一杆中断和不中断两种情况的平均值。

For the crossed steel tubes with the cross point as the middle point of member,there are some methods for calculating the effective length coefficient in codes,but there are great differences in the calculation results of these codes.A finite element model of the steel tube cross was built,and the effective length coefficient was studied,and the formulas in codes were compared.The results showed that the influence of slenderness ratio was so small and it could be neglected;the effective length coefficient under tesion and compression was suggested to use calculated value of another bar uninterrupted in Code for Design of Steel Structures（GB 50017—2003）.The effective length coefficient under compression simultaneously was suggested to use average value between another bar uninterrupted and another bar interrupted in GB 50017—2003.