The cold-formed steel members often require web openings to save interior space and allow for building services such as mechanical piping, electrical wiring, and air conditioning systems. Stress distribution in members with openings is different from members without holes, and therefore, their characteristics, shape, and modes of buckling are dissimilar which results in distinct behavior that could increase or decrease elastic buckling capacity and ultimate strength. In this study, analytical solutions for the local buckling of cold-formed steel webs with rectangular holes subjected to compression, bending and their combination are developed and summarized. The effects of flanges and other forces such as shear and torsion are not considered. The main variables are height of openings to height of web, aspect ratio of openings, and stress distribution gradient above or under the hole. These solutions can be used for a wide range of rectangular web openings for any sections. Analyses were conducted using energy-based methods, and the results were compared with numerical data obtained from the commercial finite element software (ABAQUS). The numerical results demonstrate that the three of the six proposed formulas can be used to predict the critical buckling stress of cold-formed steel webs with rectangular holes with regard to the aspect ratio of the web opening.

中文翻译：

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矩形开口冷弯型钢腹板局部屈曲分析

冷弯型钢构件通常需要腹板开口以节省内部空间并允许建筑服务，例如机械管道、电线和空调系统。有开口的构件中的应力分布与没有孔的构件不同，因此，它们的特性、形状和屈曲模式不同，从而导致可能增加或降低弹性屈曲能力和极限强度的不同行为。在这项研究中，开发并总结了矩形孔冷弯型钢腹板在受压、弯曲及其组合下局部屈曲的解析解。不考虑法兰和其他力（如剪切力和扭转力）的影响。主要变量是开口高度与腹板高度、开口纵横比、孔上方或下方的应力分布梯度。这些解决方案可用于任何截面的各种矩形腹板开口。使用基于能量的方法进行分析，并将结果与​​从商业有限元软件 (ABAQUS) 获得的数值数据进行比较。数值结果表明，六个提出的公式中的三个可用于预测矩形孔冷弯钢腹板相对于腹板开口纵横比的临界屈曲应力。