节点半刚性钢桁架受压腹杆计算长度分析  

ANALYSIS OF EFFECTIVE LENGTH OF COMPRESSIVE BRACES IN SEMI-RIGID STEEL TRUSSES

作　　者：王伟[1] 陈以一[1] 

机构地区：[1]同济大学,上海200092

出　　处：《工程力学》2005年第5期131-135,125,共6页Engineering Mechanics

摘　　要：现行设计规范对桁架腹杆计算长度的规定未考虑节点的非刚性效应,但在某些情况下该效应不能被忽略。在经典的刚架弹性稳定理论基础上推导了考虑节点刚度的四弯矩方程和构件群稳定方程,并将其应用于桁架结构。结果表明影响半刚性钢桁架腹杆计算长度的主要因素是腹杆与弦杆线刚度比和腹杆线刚度与节点局部刚度比。通过编制计算程序求取的计算长度数值解,制成了可供设计使用的计算用表和简化计算公式。以等节间Warren型钢管桁架为例证明了在腹杆计算长度分析中考虑节点刚度的意义。Current design codes have not taken into account non-rigid effect of joints in determination of effective length of truss braces, but this effect cannot be neglected in some cases. Based on classic elastic stability theory of framework, the four-moment equation and the stability equations of member group considering joint rigidity are derived and extended to study trusses. Results show that the brace to chord stiffness ratio and the brace stiffness to joint rigidity ratio are two main factors influencing effective length of braces. Tables and simplified formulae computing effective length are proposed for practical design purpose. The significance of considering joint rigidity on effective length of compressive braces is demonstrated in an example of steel tube Warren truss with equal bay span.

关 键 词：半刚性 桁架 压杆稳定 计算长度 节点刚度 相贯节点 

分 类 号：TU311.2[建筑科学—结构工程]