Influence of near-fault ground motions’ characteristics on the control performance of tuned viscous mass damper systems

Near-fault ground motions, characterized by pronounced pulse and forward-directivity effects, present significant challenges to dampers' effective performance in controlling seismic activity. This study provides an in-depth analysis of the influence of near-fault pulse-type ground motions' characteristics on the concentration of peak responses in multi-story steel frame structures, the distribution patterns of weak layer locations, and Tuned Viscous Mass Dampers' (TVMDs) effective control. The results indicate that near-fault ground motions' pulse effect, forward-directivity effect, and spectral coefficients affect the distribution of maximum inter-story drift ratios along the building height significantly. Notably, the forward-directivity effect amplifies structural responses and diminishes TVMDs control's effectiveness. In addition, ground motions with smaller spectral coefficients lead to larger inter-story drift responses. The effectiveness of TVMDs' "damping enhancement" effect is determined jointly by their mass ratio and the pulse period of the ground motion records. This study provides important theoretical foundation for the seismic design of multi-story steel frame structures and the earthquake-reduction design using TVMDs under near-fault ground motions.