Stability Analysis of Steel Columns with Fixed-Free Ends under Axial Compression: Uniform and Non-Uniform Square Hollow Sections

This study investigates the stability of steel columns subjected to axial compression, focusing on square hollow sections (SHS) with both uniform and non-uniform cross-sections. The stability of fixed-free end SHS columns with uniform cross-sections was initially verified using analytical equations. To obtain the critical load and design buckling resistance for each SHS column, Finite Element Analysis (FEA) was employed. The results indicate that while analytical equations can validate the stability of uniform SHS columns, they are insufficient for columns with non-uniform cross-sections. Consequently, the FEA emerges as a robust alternative for analyzing columns with varying cross-sections along their length. This study highlights the necessity of numerical methods for verifying the stability of structurally complex columns, such as those with perforations for mechanical and electrical applications. The finite element model was validated and applied to non-uniform cross-section columns, providing insights into the stability of these columns under practical conditions. This research aims to offer an alternative analytical approach for structural engineering applications where column stability is critical, especially for non-uniform cross-sectional designs that facilitate handling processes in various engineering scenarios.