Avaliação da resistência de ligações T entre perfis tubulares soldados em aço inoxidável com o banzo carregado axialmente

Abstract

Tubular profiles have become increasingly prominent in civil engineering as they have numerous benefits. They have a more economical geometry, a smaller surface area that favours protection against corrosion, are lighter concerning other profiles with the same resistance. Furthermore, they have high resistance to compression, torsion, bending and combined loads. For these reasons, they are commonly used in columns, trusses, and bracing elements. When tubular profiles are used, it is necessary to assess the joints' strength, considering that they can fail by different mechanisms. Several studies have been carried out on carbon steel tubular joints, but almost no work satisfactorily addresses the stainless steel tubular joints. Thereby, the present work aims to develop a formulation semi-analytically to predict stainless steel tubular T joints' resistance with axially loaded chords. Therefore, the chord side walls' contribution is determined, followed by applying the Ritz energy principle. For the validation of the data obtained by this formulation, numerical models are developed and calibrated with experimental evaluations. Additionally, the numerical models were also used in a parametric study that helped understand the joint’s behaviour when subjected to axial forces on the chord. For cases with the chord in compression, a reduction in the ultimate joint capacity was observed. On the other hand, in cases with tensioned chord, a small increase in the joint resistance was verified up to a certain level, from which it drops. A correction factor is proposed concerning the level of load applied to the chord and the chord side wall's slenderness. Finally, the proposed method's obtained results are compared to the numerical results, as well as the results from the main current standards and literature. It was observed that the proposed method, as well as the NBR 16239 design code, presented satisfactory results, while the other results were, in general, very conservative.