Top-Story Softening for Enhanced Mitigation of Vortex Shedding-Induced Vibrations in Wind-Excited Tuned Mass Damper Inerter-Equipped Tall Buildings

An innovative structural modification, top-story softening, is herein proposed in conjunction with an optimally tuned top-floor mass damper inerter (TMDI) for improved serviceability performance typical core-frame slender buildings rectangular floor plan susceptible to wind-induced vortex shedding (VS) effects causing occupant discomfort. This supported through formulating a novel optimal TMDI tuning problem which inertial properties, i.e., attached and inertance, as well the lateral stiffness are design parameters aiming minimize peak acceleration of highest occupied floor. The numerically solved wide range 34-story composite building subject stochastic spatially-correlated wind-force field accounting VS effects. A low-order dynamical model capturing faithfully modal properties case-study developed facilitate computational work parametric investigation. It found that softening reduces mass/weight requirements force fixed inertance. further stroke achieves increased robustness damping assumed inherent damping. concluded by leveraging inertance stiffness, solution can efficiently control VS-induced small additional gravitational (added weight) horizontal (inerter damping) forces.