Investigação experimental e numérica do comportamento estrutural das ligações-T bird beak diamond

Abstract

The use of steel structures through hollow section elements has been widely used. This is because the hollow sections have more advantageous properties, such as cost reduction due to the material reduction due to the tubes' greater resistance when compared to conventional sections, aesthetic appeal, ease of assembly, and efficiency in composite structures, among other benefits. Prescriptions on the dimensioning of these connections can be verified in the ABNT NBR 16239 and Eurocode 3, part 1-8 standards, in addition to other international standards. T Bird Beak (BB) joints are a more recent type of connections, initially used in trusses with square hollow sections (SHS) with one or two of its elements rotated 45°. According to the possibility of rotation or not of the profiles that make up the connections, this model has four different types of configurations. Bird Beak joints can be used for new architectural models, which can promote bolder and more attractive works for their users without increasing the cost or weight of the set. However, these connections types are recent and need research to understand their structural behaviour better. Thus, an experimental and numerical study for the traditional and BBD (Bird beak diamond) T joints was carried out, comparing the obtained results through the deformation limit criterion and existing formulas from the technical literature. It was concluded that the results compared with the literature were not satisfactory. The numerical models were developed using the finite element program ABAQUS, where the physical and geometric nonlinearities were added to the models to obtain the overall behaviour compared with the experimental. In the end, new equations are proposed to calculate the strength of BBD joints, where the results obtained show a good correlation with the experimental and numerical models developed. The proposal is analyzed through a reliability study that confirms the effectiveness of the formulas.