Shima Bijari - Department of Civil Engineering, University of Birjand, Birjand, Iran
Mohsen Khatibinia - Department of Civil Engineering, University of Birjand, Birjand, Iran

Multi Tuned mass dampers (MTMD) are widely used for reducing vibrations in mechanical and civil engineering structures. MTMD are one of the most common devices for the passive control of structures. The main purpose of this study is Optimum Design of TMD and Multi TMDs devices parameters in terms of stiffness and damping and their number. For this purpose, a ۴۰ story building has been simulated against the earthquake excitations. This evaluation is done by considering two states of soft soil and fixed base. The obtained results show that the damper has been able to perform well in reducing the response of the structure. The maximum value of the decrease in the maximum displacement of the top floor was ۲۵.۱% with ۱ TMDs, in the maximum drift of the floors was ۴۶.۷% with ۳ TMDs and in the maximum acceleration was ۰.۹۲% with ۱۰ TMDs. The optimal number of dampers is different for soft soil and fixed base.

Multi TMD, Optimum design, Seismic excitations, SSI effects, GBO algorithm.