Multi-objective optimal design of Tuned Mass Damper Inerter for base isolated structures

The BIS-TMDI is a hybrid control strategy that significantly reduces the seismic response of structures compared to conventional BIS through proper tuning, albeit with the trade-off of increased control forces exerted by the TMDI on the host building structure. However, these potentially significant forces are generally not considered in current TMDI tuning approaches. In this paper, a multi-objective optimization design method is herein developed to determine the compromise between the competing objectives of suppressing earthquake-induced vibrations in buildings and avoiding the generation of excessive control forces of TMDI. The study shows that under non-stationary excitations, the average control force of the TMDI system can be reduced by 16% compared to single optimization constraint, with a maximum reduction of up to 25%. Finally, the optimization design methods of this paper are applied to an 8-story frame as a validation case.