SEISMIC DESIGN OF STRUCTURES WITH SUPPLEMENTAL MAXWELL MODEL-BASED BRACE-DAMPER SYSTEMS

摘要

In this paper, a procedure to achieve a target performance of multi-degree-of-freedom structures with Maxwell model-based brace-damper systems is proposed. A single story structure with a viscous damper installed at the top of a Chevron-type brace is first used to investigate the effect of brace stiffness on the story displacement.Closed-form solutions relating the brace stiffness and damping coefficient to the target displacement reduction are derived for this simple structure. For a given brace stiffness, the closed-form solution is minimized to give design formulae for the optimal damping coefficient and maximum performance. The model is subsequently extended to multistory buildings with viscous dampers installed at the top of Chevron-type braces. The optimal brace stiffness and damping coefficients are obtained through an iterative process where an index, defined in terms of the sum of the mean square of the interstory drift, is minimized. The reduction in response, and hence improved performance of the structure, can be achieved by a strategic combination of the brace stiffness and viscous damper coefficients, instead of relying on damper coefficients alone as conventionally been done.