Fluid Viscous Dampers

Existing methods for the design of optimal configurations of supplemental dampers are usually not simple enough to be used routinely, and typically lead to different damper sizes at virtually every story. This can be avoided with the Sequential Search Algorithm, which lets the designer control the number of different damper sizes. In this paper, a simplification to the Sequential Search Algorithm is developed. This Simplified Sequential Search Algorithm makes it easy for engineers to deal with damper added structures. It was found that the efficiency of damper configurations given by the proposed Simplified Sequential Search Algorithm is comparable to the efficiency of damper configurations given by more sophisticated procedures. The applicability of the method is limited to those cases where the response of the structure with added dampers remains linear.

In recent years, seismic damping systems have been employed in numerous steel and concrete framed buildings. Such systems dissipate a significant portion of the seismic input energy, thereby relieving the energy dissipation demand on the structural framing system and thus reducing damage. As part of a NEESR project to develop a performance based approach to seismic design of multi-story light framed wood structures, the application of damping systems to such structures has been evaluated via seismic shaking table tests and numerical simulations. This paper focuses on the results from shaking table tests of shear walls employing toggle braced fluid dampers. The results demonstrate that toggle braced fluid dampers provide a significant increase in the seismic resistance of the walls, allowing them to achieve high levels of performance when subjected to strong ground motions.