City Research Online

Abstract

A local structural modification, namely top-storey softening, is herein considered in conjunction with optimally tuned top-floor tuned mass damper inerter (TMDI) for improved serviceability performance in mid-to-high rise buildings (host structures). The focus is to reduce floor accelerations on typical core-frame host structures with rectangular footprint due to windinduced vortex shedding (VS) effects causing occupants’ discomfort. This aim is achieved by formulating an optimal TMDI tuning problem in which TMDI inertial and top-storey host structure properties (i.e., attached mass and inertance, and top-storey height) are treated as design variables, to a case-study building aiming to minimize peak floor acceleration in the acrosswind direction. The optimal TMDI tuning problem is numerically solved for a wide range of design variables for a 34-storey composite core-frame building subject to stochastic spatiallycorrelated wind-force field accounting for VS effects. A planar low-order dynamical model capturing faithfully modal properties of the 34-storey building is developed to facilitate computational work and parametric investigation. It is found that top-storey stiffness reduction, herein regulated through storey height, not only relaxes attached TMDI mass/weight requirements, but also reduces TMDI stroke, and inerter force for fixed performance and inertance. It is concluded that by leveraging inertance and top-storey stiffness, the considered solution can efficiently control VS-induced floor acceleration with small additional gravitational (added weight) and horizontal damping forces to the satisfaction of standard code requirements for occupants comfort.

Publication Type:	Conference or Workshop Item (Paper)
Additional Information:	Copyright, the authors, 2020.
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TH Building construction
Departments:	School of Science & Technology > Engineering

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