Design of extruded and welded aluminum I‐sections

Abstract

Current standards use simplified approaches to predict the resistance of aluminum structural elements, but these often fail to capture strain hardening, instabilities and heat‐affected properties. This paper presents investigations toward an alternative design method for aluminum open cross‐sections, based on the Overall Interaction Concept (O.I.C.). This approach explicitly considers the interaction between resistance and stability, incorporates geometric and material imperfections and enables direct and consistent resistance predictions through continuous buckling curves. A validated finite element model was developed to predict the resistance of aluminum cross‐sections. Its accuracy was confirmed by comparisons with experimental data. Extensive parametric studies, covering more than 2 300 simulations, explored the influence of geometry, alloy type and loading. The results were used to formulate O.I.C.‐based design proposals for the local resistance of extruded and welded aluminum sections. The performance of these equations was assessed against reference simulations and against the Canadian, European and American aluminum design standards. The comparisons show that the O.I.C. proposals provide more accurate and consistent resistance estimates while remaining simple and efficient, offering a strong basis for improved aluminum design methods.