This paper presents an experimental and finite element (FE) investigation into the local-overall buckling interaction behaviour of axially loaded cold-formed steel (CFS) channel section columns. Current design guidelines from the American Iron and Steel Institute (AISI) and the Australian and New Zealand Standards (AS/NZS) recommend the use of a non-dimensional strength curve for determining the axial capacity of such CFS channel section columns. This study has reviewed the accuracy of the current AISI (2016), AS/NZS (2018) and Eurocode (EN 1993-1-3) design guidelines for determining the axial capacity of CFS channel sections under local-overall buckling interaction failure. A total of 40 tests were conducted on CFS channel sections covering stub, short, intermediate, and slender columns with varying thicknesses. A nonlinear FE model was then developed and validated against the test results. The validated FE model was used to conduct a parametric study comprising 70 FE models to review the accuracy of the current design guidelines in accordance with AISI (2016), AS/NZS (2018) and Eurocode (EN 1993-1-3). It was found that the AISI (2016) and AS/NZS (2018) are conservative by 10 to 15% on average when determining the axial capacity of pin-ended CFS channel section columns undergoing local-overall buckling interaction. Eurocode (EN 1993-1-3) design rules were found to lead to considerably more conservative predictions of column axial load capacity for CFS channels.This paper has therefore proposed modifications to the current design rules of AISI (2016) and AS/NZS (2018). The accuracy of proposed design rules was verified using the FE analysis and test results of CFS channel section columns undergoing local-overall buckling interaction.

本文对轴向加载的冷弯型钢（CFS）槽型截面柱的局部整体屈曲相互作用行为进行了实验和有限元研究。美国钢铁协会（AISI）和澳大利亚和新西兰标准（AS / NZS）当前的设计指南建议使用无量纲强度曲线来确定此类CFS通道截面柱的轴向承载力。这项研究回顾了当前AISI（2016），AS / NZS（2018）和Eurocode（EN 1993-1-3）设计指南的准确性，这些设计指南用于确定局部整体屈曲相互作用失效下CFS通道截面的轴向承载力。在CFS通道截面上进行了总共40个测试，这些截面覆盖了不同厚度的短，短，中和细长柱。然后开发了非线性有限元模型，并针对测试结果进行了验证。经过验证的有限元模型用于进行包含70个有限元模型的参数研究，以根据AISI（2016），AS / NZS（2018）和Eurocode（EN 1993-1-3）审查当前设计指南的准确性。研究发现，当确定经历局部-整体屈曲相互作用的销端CFS通道截面柱的轴向承载力时，AISI（2016）和AS / NZS（2018）平均保守10％至15％。欧洲规范（EN 1993-1-3）的设计规则导致对CFS通道的柱轴向承载能力的预测更为保守，因此，本文对AISI（2016）和AS / NZS（ 2018）。