Investigation of a cold-formed steel inward lipped angle section with triangular brackets under compression: Numerical and theoretical investigations

Various steel section forms, such as I, T, C-angle, and Z sections, are commonly used in construction. Among these, the angle section is particularly popular because of its flexibility in connecting with other structural members, especially in infrastructure expansion projects. This study focuses on a newly designed cold-formed steel (CFS) with an inward opening-slipped angle section, which is selected for its potential advantages in structural applications. The primary failure mode in the intermediate columns of this section is distortional buckling. To address this issue, a novel angle bracket plate is introduced to enhance both distortional and flexural buckling behavior in CFS angle columns. A total of 85 finite element models (FEMs) are analyzed. Initially, an accurate FEM was developed, validated against existing experimental data, and the strength and buckling behavior of an open CFS section under varying slenderness ratios were systematically explored. The study first evaluated the strength and buckling behavior of an open CFS section under varying slenderness ratios. It then focuses on optimizing the shape of the bracket plate, followed by an assessment of its size, location, and depth to determine the most effective configuration. Additionally, the effects of variations in the thickness, depth, and yield stress on the strength and buckling behavior are examined. Finally, this study compares the performance of open CFS inward-lipped angle sections with and without brackets across different slenderness ratios to provide a comprehensive understanding of their structural benefits.