An SSI-Informed Design for Tuned Mass Dampers With Small-to-Large Mass Ratios

Tuned Mass Dampers (TMDs) are used to mitigate structural vibrations induced by seismic or wind excitation, by tuning the device to the system's dominant resonant frequencies. However, the TMD effectiveness can be undermined by soil-structure interaction, which can lead to elongation of the vibration periods and to combined translational-rotational deformation modes. Despite its importance, this interaction is neglected in conventional TMD design. To address this gap, the present study proposes an integrated design methodology for TMDs aimed at minimising earthquake-induced effects in the superstructure, encompassing both conventional and Large Mass ratio TMDs. Optimal TMD configurations are identified through a comprehensive parametric analysis formulated in a rigorous nondimensional framework, in which soil-structure-TMD interaction is simulated by a recently developed, practice-oriented numerical model (SimilSDOF). Optimum TMD parameters are accordingly correlated to factors controlling the overall dynamic response, yielding straightforward design formulas. The proposed SSI-informed design not only avoids the occurrence of detrimental effects caused by soil-structure interaction but also leverages the dynamic response of the foundation system to enhance the TMD performance. The proposed method is validated by means of a two-stage approach: (i) an extensive investigation using the SimilSDOF, and (ii) nonlinear dynamic analyses of continuum-based, coupled soil-building models.