No abstract

The utilisation of tubular sections in steel structures has increased significantly worldwide. The use of stainless steel provides several benefits for structures, including high corrosion resistance, durability, fire resistance and ease of maintenance. A significant issue in the design of tubular structures is the joints failure since they are highly susceptible to local failures that influence their actual overall behavior. The design rules of welded carbon steel tubular joints are available, such as Eurocode 3, part 1‐8, NBR 16239, ISO 14346 and CIDECT guides. When stainless steel tubular joints are considered, the AS/NZS 4673 Australian/New Zealand Standard is the only available specification that can be used. An experimental and numerical analysis of these tubular joints are recommended since they enable a more accurate evaluation of their structural performance. Concerning these aspects, this work aims to investigate stainless steel tubular T‐joints fabricated by SHS and RHS cold‐formed profiles that focused on the effect of chord pre‐loading. For this purpose, a numerical study based on finite element analysis was performed. The finite element model was developed and calibrated against experiments. The results were subsequently compared with the aforementioned design predictions.

There are numerous benefits of tubular profiles that make them increasingly used in civil engineering. At the same time, stainless steel is a material with excellent properties and high corrosion resistance. However, stainless steel's high initial material cost has limited its use primarily to specialist and prestige applications, which makes it necessary to develop more accurate design rules for this material. When tubular profiles are used, it is necessary to assess the joint strengths, considering that they can fail by different mechanisms. The present work aims to develop a semi‐analytical formulation to predict stainless steel tubular T‐joint resistances. Joints with the brace‐to‐chord width ratio equal to 1 were considered in this study; therefore, the failure occurs in the chord sidewall. To assess the sidewall instability critical load, the exact stress fields were determined using Mathieu's theory, and then the Ritz energy method was applied. Considering that the joints are made of stainless steel, the next step is to transform the load found from linear to the non‐linear regime. For that, a new formulation based on Ramberg‐Osgood equations was developed. Finally, the results obtained from the proposed method were compared with the experimental results obtained by Feng and Young (2008) and the results from the main current standards and literature. It was observed that the proposed method presented satisfactory results, while the predictions from design codes were, in general, very conservative.