Investigation of Perforated Aluminum Alloy Stub Columns: Numerical Study and Modified Design Equations

This study numerically examines aluminum alloy square hollow section (SHS) stub columns with a single circular opening in the web. The work extends the authors’ previous experimental investigation, which indicated that selected steel-based design provisions from the American Iron and Steel Institute (AISI), the North American Specification (NAS), and the Canadian Standards Association (CSA) do not provide reliable strength predictions for aluminum alloy SHS stub columns with openings. A nonlinear finite element (FE) model incorporating geometric and material nonlinearities as well as initial geometric imperfections was developed and validated against experimental results. The validated FE model was then used to conduct a parametric investigation covering a wide range of cross-sectional geometries and opening configurations. The effects of plate slenderness ratio ( w / t ) and opening size ratio ( d / w ) on load-carrying capacity and failure modes were evaluated. Based on the numerical findings, two modified design equations were developed by adapting existing steel-based formulations. Reliability analysis and comparisons with selected existing steel-based design formulae show that the proposed equations provide improved accuracy and lower prediction scatter within the investigated parameter ranges.