Mechanical performance of T-stub connections between square concrete filled steel tubular column and steel beam

The traditional T-stub connections for beam to concrete filled steel tubular column are prone to damage in column or steel beam, which is difficult to the rapid repair after the earthquake. The connection was designed by using regular T-stub and T-stub with slotted hole as energy consumption to ensure the least or even no damage on beam or column, and to realize the replaceability of the energy consumption. Three regular T-stub connections and two T-stub connections with slotted hole were researched with numerical simulation to analyze the impact of many factors, including flange width of T-stub, flange thickness of T-stub, web width of T-stub, T-stub with slotted hole or not , the connection with anti-shear angle or not, on the hysteretic loops, the initial stiffness，ultimate rotation angle，ductility coefficient, and energy dissipation capacity. The results show that the ductility and energy consumption capacity are significantly improved respectively by T-stub with slotted hole and with anti-shear angle. The hysteretic loops of T-stub connections with slotted hole and anti-shear angle are shuttle-shaped, and energy can be consumed by friction and plastic deformation of T-stub. As for regular T-stub connections, it is suggested that the ratio of the flange width to its web thickness is less than 2.0.