摘要
直接强度法(direct strength method)是薄壁截面稳定承载力设计的一种非常简便且比较精确的设计方法,有逐步取代薄壁截面有效宽度法的趋势。应用大挠度弹塑性板壳单元对箱形柱的局部与整体相关稳定承载性能进行详细的分析,通过变化截面板件宽厚比(D/t)、截面的边长比(B/D)、构件的长细比(λ),并考虑构件实际的残余应力与几何初始缺陷,分别获得了箱形截面构件在承受轴向压力、纯弯曲以及弯矩与轴力共同作用下的稳定承载力计算公式。这些实用的计算公式摒弃了应用有效宽度法带来的误差及繁琐计算,采用直接强度法设计,其计算公式精度高,应用方便灵活,对进一步修订钢结构设计规范及工程设计有参考价值。
Box-section columns are used widely for steel frame structures. The effective width concept employed by the current Chinese code for design of steel structure is not accurate enough for predicting their ultimate load-carrying capacity where the columns are subject to plate local buckling. This paper presents a direct strength method for accurately predicting the ultimate strength of locally buckled box-section columns. An accurate shell element is used in this study to not only simulate the local buckling exactly, but also incorporate the large displacement and the elastic-plastic material in the analysis. Numbers of numerical examples were obtained and they reveal the influences of plate is width to thickness ratio, section aspect ratio and member slenderness ratio on the ultimate strength of the hollow-section members subjected to plate local buckling. With those numerical results, three simplified design formulas are respectively proposed to estimate the ultimate strength of the hollow section columns that are subjected to centrally axial load, the pure moments and the combination between them, respectively. They will be helpful in the future modification of Chinese code for design of steel structure, and the design of hollow section columns as well.
出处
《工业建筑》
CSCD
北大核心
2009年第9期41-48,共8页
Industrial Construction
关键词
箱形截面柱
稳定承载力
设计公式
box-section column
ultimate load-carrying capacity
design formula
