Seismic performance, design and placement of multiple tuned mass dampers in building applications

Extensive investigations have indicated that tuned mass dampers (TMD) are not very effective for seismic applications. One of the reasons is that both the fundamental and higher vibration modes may play important roles in the seismic responses of building structures while the conventional single TMD tuned to the fundamental mode has little effect on the responses of higher modes.; In this study, a multiple tuned mass damper (MTMD) scheme that can control the responses of multiple modes simultaneously is proposed to improve the seismic performance of TMDs. The emphasis is placed on how MTMD are distributed between the vibration modes and installed at various floors of a building structure so that the floor acceleration can be significantly reduced and the potential damage to non-structural components in the building can be minimized. A practical yet reasonably accurate procedure for optimal placement of mass dampers in building structures is developed. The effectiveness of MTMD is verified with a ¼-scale, 3-story frame structure. Numerical simulations on the seismic responses of the frame structure are in good agreement with the experimental results. Both the theoretical and experimental investigations have shown that MTMD systems are superior to a single TMD in terms of the reduction of floor acceleration. Shake table tests have confirmed that the proposed procedure gives rise to a sub-optimal design and placement of MTMD systems. In addition, the decoupling criteria for primary-secondary systems are also studied as a supplement to the study of TMD systems.