A height-aware design framework for single-tuned mass dampers in seismic steel buildings

This study presents a height-aware engineering design framework for roof-mounted single-tuned mass dampers (STMDs) in multi-story steel buildings. Five three-dimensional steel models with 5, 10, 12, 15, and 20 stories were analyzed in ABAQUS/CAE under the Kobe and Loma Prieta earthquake records. A baseline assessment first applied the Sadek tuning procedure using a fixed 5% mass ratio to investigate the influence of building height. The resulting response trends were interpreted using natural periods, modal-mass participation, a higher-mode influence index, and a detuning indicator. The 12-story model yielded the largest baseline roof-displacement reductions, reaching 46.0% under Kobe and 21.0% under Loma Prieta, whereas the corresponding reductions for the 20-story model were 12.8% and 10.7%, respectively. A surrogate-based parametric design exploration was subsequently used to examine practical combinations of mass ratio, tuning ratio, and damping ratio within prescribed bounds. The surrogate exploration identified candidate parameter sets that substantially mitigated dynamic demands in low- and mid-rise structures; however, it failed to overcome the intrinsic modal-dispersion bottleneck in the 20-story frame. For that model, combining the STMD with shear walls or outer inverted-V bracing increased the roof-displacement reduction to 45.4–65.5%, depending on the earthquake record and lateral-resisting configuration. The proposed sequence height screening, parameter exploration, and hybrid-system assessment provide a structured design process for selecting the control strategy within the investigated building family. However, the control efficacy of standalone STMDs remains fundamentally limited in taller, flexible buildings due to higher-mode mass participation and nonlinear frequency detuning. The present findings are bound by the investigated prototype steel frames, uniform cross-sectional benchmark assumptions, fixed-base boundary conditions, and the selected ground motion records.