Mitigation of stress concentration in a diagrid structural system using circular steel tubes

The diagrid structural system has been in the spotlight because of its superiority in terms of its resistance to lateral forces when applied to skyscrapers. In the diagrid structural system, most columns can be eliminated because the vertical loads (gravity loads) and horizontal loads (lateral loads) are delivered simultaneously due to the triangular shape of the diagrid module. Despite this increasing interest, few studies have examined the connection shape and details, which has made it difficult to employ the system to the buildings. In this study, the structural safety of the node connections in a circular steel tube diagrid structural system, which has been considered in the Cyclone Tower in Korea (Seven stories below and fifty-one above the ground), was evaluated using finite element analysis and 4 full-scale specimens.