Study of the behaviour of welded joints composed of elliptical hollow sections

摘要

Latest product of the hollow section family, the elliptical hollow section (EHS) from Arcelor Tubes allows the architects to realise light and transparent constructions. But its use requires the development of design and conception procedures for the welded connections between these profiles. Because of the recent arrival of the EHS on the market, design recommendations aren't available for this kind of connections. Nowadays these connections have to be checked by the experimental way, what is rather expensive. Therefore it is imperative to develop numerical models and analytical methods for the prediction of the resistance and ductility properties of elliptical hollow section joints. Moreover, present code recommendations for the calculation of tubular (circular and rectangular) connections are based on empirical formulations. But the current tendency for the connection design is to derive analytical formulae based on the so-called "component method" (Eurocodes 3 and 4). The purpose of this work is to investigate this topic. The resulting diploma work represents a first step in the development of connections between EHS profiles. It could therefore not be possible, in the framework of this diploma work, to derive the final analytical formulae for the calculation of elliptical connections. The objectives of this work which focuses on the behaviour of simple brace to chord joints were then the following: acquire a good knowledge of the physical behaviour of EHS connections, develop reliable numerical models to allow Arcelor to check easily some real cases and finally propose a background for an analytical formulation for the resistance of the joint.