Development of box-shaped steel slit dampers for seismic retrofit of building structures

In this study a steel slit damper is developed by combining four steel slit plates to be used for seismic retrofit of structures. The proposed damper consists of four slit plates integrated into a box shape, and can produce larger damping force in relatively small size compared with the conventional slit plate dampers composed of single slit plate. Cyclic loading tests of two damper specimens are carried out to evaluate their seismic energy dissipation capability. The slit dampers are applied to seismic retrofit of an existing reinforced concrete structure using the procedure developed based on the capacity spectrum method. Nonlinear dynamic analysis of the model structure shows that the dampers installed using the proposed procedure are effective in restraining the building displacement within a given target performance limit state. The time history of the hysteretic energy dissipation shows that most seismic energy is dissipated by the dampers while the structural elements mostly remain elastic.