RESUMEN
Squared hollow steel profiles are commonly used in the construction of offshore structures or building facades. By welding two or more pipes, typical joints are created that are specific for different areas of applications. These joints are less resistant than straight pipes due to the geometrical heterogeneity and the complex stress behavior of the welding. Standards define these joints, but there are restrictions imposed regarding the material or geometry. This paper focused on full-overlapped joints with squared hollow section profiles and on-top connection, which are disregarded in current standards. The aim was to figure out the influence of the inclination angle on the resistance of the joint. In the analysis, experimental and numerical studies were performed. Four different inclination angles commonly used on construction sites were the focus. It was discovered that there is a total diminishment of 46% in the load bearing capacity between the steepest and the most obtuse angles. The structural behavior is non-linear and is influenced by the value of the angles. The second aspect is related to the influence of the steel profile, which is evaluated by a comparison between a squared profile and two circular profiles. It was discovered that the joint made with squared profiles has a higher bearing capacity than the one made with circular profiles, a statement valid for similar thicknesses of the elements.
RESUMEN
Steel hollow section joints are mainly used for offshore structures, hall support or trusses. Current standards define different kinds of steel joints, but there are limitations regarding the geometry or load scenarios. Excluded joints are full-overlapped Y-joints with on-top connection. For these kinds of joints, there is no general design fundamental, so the design engineer has to build his/her own model. The aim of this paper is to figure out the resistance of this special undefined joint type and the influence of the inclination angle between the pipes. An experimental and numerical analysis of this joint was done. Due to this evaluation of the inclination angle, the design engineer could optimize the structure economically. Two different circular profile types were focused on. It was concluded that by increasing the inclination angle, the total applicable force decreased non-linearly. On one hand, the most economic design was achieved by choosing a steep angle. On the other hand, the resistance of the structure, regarding the maximum appliable force, could be increased. For the system in this paper, an increase up to 47% was achieved by choosing a profile with a thickness of 2.8 mm instead of 2.0 mm.
RESUMEN
Steel joints made out of circular hollow section profiles are used for many fields of applications, such as wide-span or representative halls for airports. By connecting two inclined pipes to a vertical third pipe, a ramified vertical column is created, where the node is the weakest point in the structure due to the geometrical heterogeneity. The current standards and Design Codes have limitations regarding the geometrical properties of hollow sections joints. However, the kind of steel joint presented in this paper is excluded in the current standards. This paper is about numerical FEA case studies of two-dimensional, circular hollow-section joints to figure out the resistance of atypical steel joints. In the first step, a small-scale model is generated to analyze the influence of the inclination. In the second step, the geometries of the different pipes are extended. The influence of the inclination angle and the stability of the joint are analyzed. It was discovered that the inclination angle between the three pipes has a large influence on the stresses and deflections at the node. By increasing the inclination angle, the maximum applied force can be increased. The extended members change the behavior and the stress distribution.
