Using Hybrid Isolation Systems with Friction Dampers for Seismic Protection of Structures
Yuri Ribakov, Grigoriy Agranovich
Seismic isolation of structures is one of the most popular ways for design of earthquake resistant buildings all over the world. It results in improvement in structural behavior during earthquakes however the base isolators’ displacements are rather big. Addition of dampers to a base isolator is a common way for reduction of base displacements. Using additional active or semi-active dampers aimed to achieve optimal structural behavior is also good known. This study id focused on a method for selection of friction dampers properties based on optimal active control algorithms. The aim of the design is to select the passive friction dampers properties so that the seismic response of a base isolated structure with these dampers would be as close as possible to that of a structure with optimally controlled active damping devices. Such behavior is achieved if the energy dissipated in passive friction dampers will be equal to that in active controlled devices. The efficiency of the proposed method is demonstrated in a numerical example. Behavior of a base isolated structure with supplemental passive friction dampers designed according to three various strategies is compared. It is shown that the proposed method yields a structural seismic response that is more similar to that if an active control system is used.