Evaluation of Seismic Performance of Double-layer Steel Diagrid Systems
A new type of structural systems, called diagrid, has been introduced in recent years, in which the diagonal members are often located in the exterior frames while the interior frames, including vertical columns, resist only the gravity loads. A novel double-layer diagrid system is proposed in this study and the equations related to its lateral stiffness are extracted. The combination of angles of internal and external diagonals is also investigated to obtain the desired stiffness. Eventually, considering a 12-story structural model, the seismic performance of the proposed system is investigated and compared with conventional diagrid systems through changing the angle of diagonals in interior and exterior frames. Results show that double-layer diagrid systems are more suitable than conventional diagrid systems in providing stiffness and strength criteria. Moreover, a proper combination of internal and external angles improves the ductility, as well as increasing the amount of energy dissipated by the structure.