Special Truss Moment Frames Equipped with Steel Slit Dampers

Truss moment frame (TMF) is one of the common lateral load resisting systems for structures with long spans. To avoid developing plastic hinges in the columns, which reduces the ductility of TMFs significantly, special truss moment frames (STMFs) have been offered as a more suitable alternative. In this system, the mid-span of the truss girder is replaced by a single-panel Vierendeel special segment. In conventional STMFs, energy dissipation is due to the development of plastic hinges at two ends of the upper and lower chord members of the special segment. This study aims to propose a modified system by using steel slit dampers (SSDs) in the special segment of STMFs. The efficiency of the proposed system is investigated using experimentally validated Finite Element (FE) models. A comprehensive analytical study is carried out on different parameters of one-bay one-story STMFs equipped with SSDs. Subsequently, the seismic performance of 4, 6, 8, and 10-story STMFs equipped with SSDs is studied. The results indicate that the application of SSDs in the special segment of STMFs can significantly improve the energy dissipation of the system (up to 350%) and increase the cumulative displacement capacity (up to 100%). Therefore, the proposed system can serve as a suitable structural system to resist both gravity and lateral loads in long-span structures.