Full-scale cyclic testing of an innovative energy dissipating device for seismic resiliency

Metallic dissipaters, which dissipate seismic energy by plastic deformation of the metal, have been most widely used in building construction to achieve seismic resilience. In this research, an innovative metallic dissipater called multiple U-shaped flexural plates (UFP) dissipater (MUD), was discussed. MUD can be used as a bracing member in eccentrically or concentrically braced frames. It has three main components: internal core member (usually steel universal column), external casing member (usually steel hollow section) and UFPs. UFPs are bolted between the internal and the external members in pairs. The internal (movable) and external (fixed) members can move relative to each other by rolling motion of the UFPs under axial compression and tension. This paper presents the experimental findings of four quasi-static cyclic tests of the MUD with varied displacement amplitudes and loading rates. Deformation behavior, hysteretic response, equivalent viscous damping ratio, energy dissipation capacity and other structural performance are investigated. The experimental results show that the MUD is able to achieve stable and repeatable hysteresis performance. All specimens can meet the cumulative inelastic deformation criteria in ANSI/AISC 341-16. The last specimen was tested until the capacity decreased by 30% to study the failure behaviour. The results show that the MUD has a promising ability to maintain strength after initiation of fracture and to prevent sudden failure of the structure.