The paper addresses the issue of local buckling of compressed flanges of cold-formed thin-walled channel columns and beams with nonstandard flanges composed of aluminium alloys. The material behaviour follows the Ramberg–Osgood law. It should be noted that the proposed solution may be also applied for other materials, for example: stainless steel, carbon steel. The paper is motivated by an increasing interest in nonstandard cold-formed section shaping in local buckling analysis problems. Furthermore, attention is paid to the impact of material characteristics on buckling stresses in a nonlinear domain. The objective of the paper is to propose a finite element method (FEM) model and a relevant numerical procedure in ABAQUS, complemented by an analytical one. It should be noted that the proposed FEM energetic technique makes it possible to compute accurately the critical buckling stresses. The suggested numerical method is intended to accurately follow the entire structural equilibrium path under an active load in elastic and inelastic ranges. The paper is also focused on correct modelling of interactions between sheets of cross section of a possible contact during buckling analysis. Furthermore, the FEM results are compared with the analytical solution. Numerical examples confirm the validity of the proposed FEM procedures and the closed-form analytical solutions. Finally, a brief research summary is presented and the results are discussed further on.

中文翻译：

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铝合金槽型法兰的局部稳定性问题

本文探讨了冷弯薄壁槽形立柱和带有铝合金非标准法兰的梁的压缩法兰的局部屈曲问题。物质行为遵循Ramberg-Osgood定律。应当注意，提出的解决方案也可以应用于其他材料，例如：不锈钢，碳钢。这篇论文的动机是对局部屈曲分析问题中非标准冷弯型材的日益增长的兴趣。此外，要注意材料特性对非线性域中屈曲应力的影响。本文的目的是在ABAQUS中提出一种有限元方法（FEM）模型和相关的数值程序，并辅以一种解析方法。应当注意的是，所提出的FEM能量技术使精确计算临界屈曲应力成为可能。建议的数值方法旨在在弹性和非弹性范围内的有效载荷下准确地遵循整个结构平衡路径。本文还将重点放在屈曲分析期间可能接触的横截面之间的相互作用的正确建模。此外，将有限元结果与分析解决方案进行比较。数值例子证实了所提出的有限元程序和封闭形式的解析解的有效性。最后，给出了简短的研究总结，并对结果进行了进一步讨论。建议的数值方法旨在在弹性和非弹性范围内的有效载荷下准确地遵循整个结构平衡路径。本文还将重点放在屈曲分析期间可能接触的横截面之间的相互作用的正确建模。此外，将有限元结果与分析解决方案进行比较。数值例子证实了所提出的有限元程序和封闭形式的解析解的有效性。最后，给出了简短的研究总结，并对结果进行了进一步讨论。建议的数值方法旨在在弹性和非弹性范围内的有效载荷下准确地遵循整个结构平衡路径。本文还将重点放在屈曲分析期间可能接触的横截面之间的相互作用的正确建模。此外，将有限元结果与分析解决方案进行比较。数值例子证实了所提出的有限元程序和封闭形式的解析解的有效性。最后，给出了简短的研究总结，并对结果进行了进一步讨论。数值例子证实了所提出的有限元程序和封闭形式的解析解的有效性。最后，给出了简短的研究总结，并对结果进行了进一步讨论。数值例子证实了所提出的有限元程序和封闭形式的解析解的有效性。最后，给出了简短的研究总结，并对结果进行了进一步讨论。