A Multi Tuning-Frequency Passive/On-demand Active Pendulum Tuned Mass Damper

Abstract

The use of tuned mass dampers (TMDs) in high-rise buildings, towers, and other tall structures for mitigating wind-induced vibration has resulted in significant improvements in serviceability of such structures. In applications where more than one mode of vibration with distinctly different natural frequencies are in need of damping, multiple passive TMDs each tuned to one of the natural frequencies are needed. In many such applications, the excessive cost, weight, and space requirement of multiple passive TMDs are not acceptable. This paper presents a novel passive pendulum tuned mass damper (PTMD) which on-demand can switch to an active PTMD. In its default passive state, the proposed device is tuned to the first mode of the structure and acts as a traditional passive PTMD. In its active state, while staying tuned to the first mode passively, the PTMD simultaneously tunes itself to multiple higher order modes adding tuned damping and providing a multi-directional vibration control.