相邻腹杆刚度对桁架受压腹杆计算长度的影响

Influence of Adjacent Brace Rigidity on Effective Length of Compressive Brace in Trusses

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的计算方程,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,文中建议的计算方法更具一般性.计算及分析结果表明:考虑计算节点处相邻腹杆刚度的约束后,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,按文中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小.

According to the classical elastic stability theory of framework and the related research results, the stability equations of member bar group and the equations to calculate the effective length coefficient of compressive brace are deduced by considering the joint rigidity and the adjacent brace rigidity. Then, the tables for the calculation of effective length of compressive brace in truss are provided for engineering application. As compared with the existing calculation methods, the proposed equations are more general. Calculated and analytical results show that, by considering the rigidity restraint of the adjacent braces at the calculating joint, the calculated effective length of compressive brace in truss slightly decreases, and that, within most range of the rigidity ratio, the calculated effective length coefficients are smaller than those provided by current criteria.