Wind-induced coupled lateral-torsional response of tall buildings using bidirectional tuned mass damper inerter

This study investigates the wind-induced coupled lateral-torsional responses of tall buildings and evaluates a bidirectional tuned mass damper inerter (BTMDI) for vibration control. A 34-story benchmark building, consisting of steel moment-resisting frames and a reinforced concrete core, was analyzed under along-wind, across-wind, and torsional loads using frequency-domain dynamic analyses. Four structural configurations were considered to examine the effects of stiffness asymmetry, achieved through asymmetric bracing layouts, and overall lateral stiffness. Torsional responses arising from both stiffness eccentricity and aerodynamic excitation were explicitly addressed. The performance of the BTMDI was assessed for three representative inerter topologies spanning different numbers of stories, enabling a systematic evaluation of inerter engagement effects. Results for the uncontrolled building showed that combined torsional effects substantially amplified roof displacements and diaphragm accelerations, particularly near the corners, highlighting the importance of effective vibration control in tall buildings. The BTMDI significantly reduced roof displacements (up to ∼40%), torsional rotations (up to ∼20%), and RMS accelerations (up to ∼50%), with greater effectiveness in configurations with asymmetric stiffness and multistory inerter layouts; moreover, increasing the inertance ratio primarily enhanced acceleration-based performance compared to a conventional bidirectional tuned mass damper (BTMD), confirming the inerter’s role in improving vibration serviceability rather than peak displacement demands.