ABSTRACT
This chapter proposes a method for finding the optimal distribution of stiffnesses of hysteretic dampers with gap mechanism in building structures for pulse-type earthquake ground motions of extremely large amplitude. This damper system is a part of the hysteretic-viscous hybrid (HVH) damper system composed of parallel-type viscous and large-amplitude hysteretic dampers with gap mechanism or the dual hysteretic damper (DHD) system composed of parallel-type small and large-amplitude hysteretic dampers. It was found in the previous papers that the HVH system and the DHD system have an almost equivalent damper performance. However, the independent analysis of the property of the large-amplitude hysteretic dampers with gap mechanism as a stopper system for extremely large earthquake ground motions has never been conducted. For this purpose, an optimization problem for stiffness distributions of large-amplitude hysteretic dampers with gap mechanism is posed and its solution algorithm is developed. Then, the optimal trigger displacements of those dampers are also investigated. A double impulse is used here as a substitute of pulse-type ground motions of extremely large amplitude and only the critical double impulse resonant to the elastic-plastic response is treated.
