Optimal distribution of friction dampers for seismic retrofit of a reinforced concrete moment frame

This study investigated the story-wise optimal distribution of friction dampers to effectively reduce the seismic response of a reinforced concrete structure designed without considering seismic load. To this end, a genetic algorithm process was applied and the results were compared with those obtained by simple intuitive method based on story drift. The seismic performance of the model structure with optimally positioned friction dampers was evaluated by nonlinear static and dynamic analyses. The analysis results showed that compared with the system without friction dampers, the maximum roof displacement and the inter-story drift ratio were reduced by about 30% and 40%, respectively, after installation of the dampers. In comparison with the intuitive method of installation, the genetic algorithm provided an efficient solution for optimum damper distribution with less amount of friction damper.