Seismic response of multi-story structure with multiple tuned mass friction dampers

The effectiveness of passive multiple-tuned mass friction dampers (P-MTMFDs) over a single passive-tuned mass friction damper (P-TMFD) is investigated. The governing differential equations of motion are solved numerically using state-space method. The response of a five-story structure is investigated for four considered earthquake ground motions. The number of P-TMFD units of P-MTMFDs is varied and the response of five-story structure with single P-TMFD is compared with the response of the same structure with P-MTMFDs. A parametric study is also conducted to investigate the effects of important parameters like number of P-TMFD units in P-MTMFDs, frequency spacing, mass ratio, tuning ratio and damper slip force. It is found that at a given level of excitation; an optimum value of considered important parameters exists at which the peak displacement of structure attains its minimum value. The response time history of the structure with single P-TMFD and P-MTMFDs, with respect to their optimum parameters is compared. It is found that the P-MTMFDs are more effective in controlling the response of the structure to which it is attached in compare to the single P-TMFD having same mass.