相邻腹杆刚度对桁架受压腹杆计算长度的影响

以经典的刚架弹性稳定理论以及相关研究成果为基础，推导了考虑节点刚度和相邻腹杆刚度对受压腹杆影响的杆件群稳定方程以及腹杆计算长度系数计算方程，给出了可供工程使用的桁架腹杆计算长度用表。和现有的腹杆计算长度系数计算方法相比较，本文建议的计算方法更具有一般性。计算分析结果表明，考虑计算节点处相邻腹杆刚度的约束作用后，桁架中间受压腹杆的计算长度有所减小；在大多数刚度比范围内，按本文方法计算的中间和端部受压腹杆的计算长度系数比现行规范的取值小。

Influence of Joint Rigidity and Brace rigidity on Effective Length of Compressive Brace in Truss

The stability equations of member bar group and the equations of calculating effective length coefficient of compressive brace in truss considering joint rigidity and brace rigidity of the same joint are deduced based on classical elastic stability theory of framework and related research results. The tables of calculating effective length coefficient of compressive brace in truss are also provided to the engineering application. Compared with current calculation methods of the calculating effective length coefficient of compressive brace in truss, the method suggested by the study is more generality. The analysis results shows that, considering the restraining effects of adjacent braces’ rigidity at calculating joint, the calculating effective length coefficient of compressive brace in truss shows a little reduction; and in the most range of stiffness ratio, the values of the calculating effective length coefficient of compressive brace in truss calculating by the suggested method are smaller than those of by current codes.