Effect of strengthening and infill concrete on bending behavior of Y and T shape connections

One of the most commonly joints in steel tube structures that are widely used in plate trusses and spacecraft, power towers, steel structures and offshore platforms, is Y and T joints. In this study, a numerical study of in-plane bending load on square and Y-shaped composite joints is investigated. In this study, 27 Y-joint and 27 T-joint specimens were simulated using Abaqus software. Parameters included diaphragms, concrete-filled steel tube chord and dimension change in brace member and angel of brace-chord member is 45 and 90 degrees. The results showed that the presence of concrete inside the core member, in addition to the concrete confinement, increases the flexural strength of the joint and its stiffness. Concrete delays the local buckling mode of the panel zone and improves bending behavior compared to the hollow sections.