弯曲型支撑-框架的假想荷载法

NOTIONAL LOAD APPROACH FOR FLEXURAL BRACING-FRAME

为避免在钢结构设计中逐一去确定框架柱的计算长度,该文提出了一种应用于弯曲型支撑框架的假想荷载法。将假想荷载作用于框架楼层,配合二阶弹性分析,考虑材料非线性、残余应力和初始几何缺陷,研究了多种几何和荷载条件下的弯曲型支撑框架模型,分析了一系列模型的极限承载力,提出了统一的假想荷载系数以及假想荷载的近似公式,无论是有水平荷载或无水平荷载,无论是等截面还是变截面,其结果与有限元结果都符合较好。

A notional load for flexural bracing frames is proposed to avoid determining the effective length of columns in the design of steel structures. Notional loads are applied on the frame stories, with second-order elastic analysis, considering the material nonlinearity, residual stress and initial geometric imperfections, a flexural bracing frame model under a variety of geometry and load conditions and a series of the ultimate bearing capacity are analyzed, and then the notional load coefficient and the approximate formula of the notional load are proposed It is found that the results with finite element results are in a good agreement no matter with or without horizontal load, and no matter a uniform cross-section or a variable cross-section.