EACS 2016 paper - Control of across-wind vortex shedding induced vibrations in tall buildings using the tuned mass-damper-inerter (TMDI)

2017-03-28T15:19:41Z (GMT) by Francesco Petrini Agathoklis Giaralis
<div>EACS 2016 Paper No. 126</div><div><br></div>In this paper, the effectiveness of the tuned mass-damper-inerter (TMDI) vis-à-vis the classical tuned mass-damper (TMD) is assessed to suppress vortex shedding induced vibrations to tall building structures in the across-wind direction. The TMDI, previously proposed in the literature to mitigate earthquake-induced vibrations in multi-storey buildings, benefits from the mass amplification effect of the inerter (i.e., a two-terminal device developing a resisting force proportional to the relative acceleration of its terminals by the inertance constant) to achieve improved vibration suppression performance from the classical TMD for the same attached mass. Herein, a linear reduced-order structural system is developed, defined by a diagonal mass matrix and full damping and stiffness matrices, which captures faithfully the dynamic properties of a detailed finite element model corresponding to a benchmark 74-storey building with square floor plan. A TMDI is added to the structural system by elementary operations to the mass, damping, and stiffness matrices under the assumption of an ideal linear inerter. The wind action is represented by an analytical spectral density matrix modelling correlated across-wind induced forces accounting for vortex shedding and the structural analysis step is undertaken in the frequency domain for efficiency. A comprehensive parametric analysis is undertaken demonstrating that the TMDI achieves better performance in terms of peak top floor acceleration reduction with increasing inertance than a classical TMD with the same attached mass. This is also true for relatively small attached masses of practical interest to tall buildings (less than 0.5% the total buildings mass) for the case of peak top floor displacements. Further, it is shown that the TMDI reduces significantly the peak attached mass displacement, while the peak developing forces at the inerter are not excessive and can be locally accommodated by the building.