Optimum design and application of non-traditional tuned mass damper toward seismic response control with experimental test verification

A variant type of tuned mass damper (TMD) termed as 'non-traditional TMD (NTTMD)' is recently proposed. Mainly focusing on the employment of TMD for seismic response control, especially for base-isolated or high-rise structures, this paper aims to derive design formulae of NTTMDs based on two methodologies with different targets. One is the fixed points theory with the performance index set as the maximum magnitude of the frequency response function of the relative displacement of the primary structure with respect to the ground acceleration, and the other is the stability maximization criterion (SMC) to make the free vibration of the primary structure decay in the minimum duration. Such optimally designed NTTMDs are compared with traditional TMDs by conducting both numerical simulations and experiments. The optimum-designed NTTMDs are demonstrated to be more effective than the optimum-designed traditional TMDs, with smaller stroke length required. In particular, the effectiveness of the TMDs combined with a base-isolated structure is investigated by small-scale model experimental tests subjected to a time scaled long period impulsive excitation, and it is demonstrated that the SMC-based NTTMD can suppress structural free vibration responses in the minimum duration and requires much smaller accommodation space. Additionally, a small-scale shaking table experiment on a high-rise bending model attached with a SMC-based NTTMD is conducted. This study indicates that NTTMD has a high potential to apply to seismic response control or retrofit of structures such as base-isolated or central column-integrated high-rise structures even if only a limited space is available for accommodating TMDs.