K形偏心支撑钢框架的弹性抗侧刚度与极限承载力

The elastic lateral stiffness and ultimate capacity of K-eccentric braced steel frames

为了明确K形偏心支撑的传力路径和内力分配,便于计算层间侧移和耗能连梁转角,依据结构力学基本假定,给出了K形偏心支撑框架各构件在侧向力作用下的内力表达式,进而推导出K形偏心支撑弹性抗侧刚度的近似计算公式,通过试验数据和ANSYS有限元分析,验证了公式的精确性,并提出了K形偏心支撑构件的简便设计方法;基于虚功原理和小变形假定,当已知外力分布时,依据偏心支撑达到极限状态时的典型屈服机制,推导出K形偏心支撑极限承载力公式,利用SAP2000对10层算例进行推覆分析,验证了极限承载力公式,为工程设计提供参考依据.

In order to identify the loading path and internal force distribution of K-eccentric braced steel frames, and compute story drift and link rotation conveniently, based on the fundamental assumption of structural mechanics, the formulas of elastic internal forces of K-eccentric braced steel frames subjected to lateral loads have been proposed. The elastic lateral stiffness approximate formula of K-eccentric braced steel frames is then derived, and the formulas are well-supported by the experimental data and finite element analysis. Simple and convenient design method of K-eccentric braced frames is proposed. When lateral load distribution was known, the formula of ultimate capacity of K-eccentric braced steel frames is derived based on virtual work principle, small deformation assumption and typical yielding mechanism of ultimate state. Pushover analysis of 10-storey K-eccentric braced steel frame is conducted by finite element soft-ware SAP2000, and the analysis result confirmed well with the calculation of formula. The formula of ultimate capacity can provide a reference for structure design of K-eccentric braced steel frames.