Optimal placement of metallic dampers for seismic upgrading of multistory buildings based on a cost-effectiveness criterion using genetic algorithm

In this paper, an optimal placement methodology for metallic dampers is proposed to upgrade the seismic performance of multistory buildings. Most previous studies on optimal damper placement (ODP) problems have been focused on minimizing the seismic responses, whereas the present study aims to utilize the minimum total cost of dampers to achieve a prescribed level of seismic response. To this end, the optimization objective is constructed based on a cost-effectiveness criterion, and the optimization constraint is defined based on a desired level of seismic response. An improved integer-coded genetic algorithm is presented for solving the ODP problem. A 16-story shear building is illustrated to verify the proposed optimal placement methodology. It is shown that the proposed methodology can be used to achieve the predetermined performance level while minimizing the retrofitting cost. Moreover, different algorithms, objective functions, and levels of accuracy on the optimization are also compared. Finally, a two-step optimization approach is proposed for achieving better placement schemes with less computational efforts.