Improving seismic performance of non-ductile reinforced concrete frames through the combined behavior of friction and metallic dampers. (1st October 2018)

• Record Type: Journal Article
• Authors: Lee, Chang-Hwan; Ryu, Jaeho; Kim, Do-Hyun; Ju, Young K.
• Is Part Of: Engineering structures. Volume 172(2018)
• Page Start: 304
• Page End: 320
• Publication Date: 2018-10-01
• Subjects: Hybrid damper -- Reinforced concrete frame -- Seismic performance -- Non-ductile detail -- Energy dissipation -- Ductility -- Stiffness -- Cyclic loading -- Seismic resilience; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2018.06.045
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: A seismic strengthening technique using a wall-type damping system (DS) is described. Progressive damage states of a non-ductile RC frame are presented according to the story drift level. Strengthened frames demonstrated improved strength, stiffness, and energy dissipation. Due to anchorage softening, the stiffness of the DS was significantly lower than theorized. Abstract: This paper describes a seismic strengthening technique using a wall-type damping system (DS), targeted at moment-resisting frame buildings. The DS under consideration is a hybrid damper which works through the combined and multi-phase action of a friction damper (FD) and a metallic damper (MD). To assess the seismic effectiveness of the proposed system, full-scale cyclic tests were conducted on a bare reinforced concrete (RC) frame with non-ductile detailing and four damper-strengthened frames. The RC frame showed highly pinched behavior, whereas the hysteresis curves of strengthened frames were more stable due to the activation of FD and/or MD, forming a larger loop area. The deformation capacities of the RC frame and strengthened frames were not significantly different, but the maximum strength, stiffness, and energy dissipation capacities were significantly improved in the strengthened frames. The calculated strength and stiffness equations accurately represented the actual behavior of the RC frame. Conversely, the stiffness values of the DS were considerably lower than predicted by theoretical equations as a result of the softening of anchorage fixity according to the connection details.