Optimum multiple tuned mass dampers for soft story structures

Soft-story structures often suffer damage and collapse during earthquakes due to different vibrations and movement of the ground beneath them, while higher stories are more stable. From this point, this study focuses on implementing multiple-tuned mass dampers (MTMDs) system into a soft-story structure, which is a single TMD placed on each floor of the structure, to investigate its effectiveness in mitigating dynamic responses during seismic excitation. As known, tuned mass dampers (TMDs) are a popular passive control mechanism used to reduce undesirable vibrations in structures by absorbing lateral loads from primary systems. This study was established by using Jaya metaheuristic algorithm (JA) as a fundamental optimization method, which was used for tuning passive mass dampers. In addition, Den Hartog technique has been used as well to optimize the TMD parameters. The numerical optimization of Jaya algorithm, and the application of Den Hartog equations have been performed using Matlab (R2018a) programming. Thus, TMD parameters such as period, damping, mass, and frequency have been estimated. The process of this study was carried out utilizing a two-story model with two different separated TMDs placed on each for a set of cases. This model was loaded by 44 sets of earthquakes, which have recorded by FEMA P-695, and has been analyzed using MATLAB program according to both of Den Hartog technique and Jaya metaheuristic algorithm. The used model was examined and compared to another model that contains a single TMD on the top floor, and to another model that does not consist of any TMD. The results of this study show an improvement results by using multiple TMD analyzed by Jaya metaheuristic algorithm compared to those analyzed by Den Hartog technique in order of mitigate displacement.