Thin-walled channel beams are easily punched with circular holes on the web to allow the access for services such as plumbing pipes and electric wires. The presence of the holes can alter the stress distribution in the member and reduce the cross-sectional property. Consequently, it changes its buckling mode. Since perforated cold-formed steel beams are usually placed between main structural frame and corrugated roof, the most common loading case is the uniformly distributed transverse load. Recent work by Chen and Li has given the solution for distortional buckling of channel-, zed- and sigma-sections subject to the uniformly distributed transverse load. This paper is an extension of Chen and Li's research to explore the distortional buckling behaviour of perforated cold-formed steel beams with holes. The effect of perforations on the critical stress is evaluated. A new model is deduced to predict the critical stress of distortional buckling by reducing the stiffness of the vertical spring. The Rayleigh-Ritz method is used to solve eigenvalue problems. In order to validate the analytical model, finite element analyses have been performed by using ANSYS. When the beam is longer than 3500 mm, the critical stress computed from the analytical model matches well with the critical stress acquired from the finite element analyses.

薄壁槽形梁很容易在腹板上打出圆孔，以便接入水暖管道和电线等服务。孔的存在会改变构件中的应力分布并降低截面特性。因此，它会更改其屈曲模​​式。由于穿孔的冷弯型钢梁通常放置在主结构框架和波纹屋顶之间，因此最常见的荷载情况是横向荷载均匀分布。Chen和Li的最新工作给出了在均匀分布的横向载荷作用下，通道，zed和sigma截面变形屈曲的解决方案。本文是对Chen和Li的研究的扩展，以探讨带孔的多孔冷弯型钢梁的变形屈曲行为。评估了穿孔对临界应力的影响。通过减小垂直弹簧的刚度，推导出一个新模型来预测变形屈曲的临界应力。Rayleigh-Ritz方法用于解决特征值问题。为了验证分析模型，已通过使用ANSYS进行了有限元分析。当梁长于3500 mm时，从解析模型计算出的临界应力与从有限元分析获得的临界应力非常匹配。