Resistance of elliptical hollow section T-joints subjected to in-plane bending moment

The production of profiles known as "Elliptical Hollow Section" (EHS) in recent years and translated to Turkish as "Elips Enkesitli İçi Boş Profil" has become popular because of their aesthetic appearance and advantages in the structural engineering. However, there is no any analytical methods in regulations to calculate the resistance of the joints made of Elliptical Hollow Section (EHS). As these profiles have two different diameters, the joints can form in four different orientation types. The resistance of these profiles are generally calculated by simulating to the profiles which are known as "Rectangular Hollow Section" (RHS) and translated to the Turkish as "Dikdörtgen Enkesitli İçi Boş Profil". This approach is called equivalent rectangular section profile method. In this method, it is assumed that the width and depth of RHS members are equal to the small and large diameters of EHS member and resistance of EHS joints may be calculated based on the equivalent RHS method in regulations. However, the literature researches have shown that equivalent RHS method may not give safe and economic results for each orientation. The purpose of this study is to investigate the failure modes and the resistance of EHS T-joints subjected to in-plane bending moment by using equivalent RHS method in available design guides. In this study, numerical analyses have been carried out by using non-linear finite element software, ABAQUS v6-14.1. Before numerical analyses have been done, finite element model has been validated with an available test result. According to this validation study, finite element type, material type, mesh size and parameters such as time step which are handled in non-linear numerical analyses used for parametric studies. A series parametric study was carried out by considering the orientation types of EHS T-joints and geometrical parameters of main members. Numerical results have been compared to analytic results based on equivalent RHS method. According to these results, it has been found that this method is conservative. Moreover, it has been noted that type 1 and type 2 have similar resistance and behaviour with type 3 and type 4 orientations. In this thesis, a safe and economic calculation method has been introduced and this method has been verified by comparing with numerical results.