Adaptive Configuration Tuned Mass Damper for Mitigation of Rotational Vibrations

Abstract

An innovative design for an adaptive configuration tuned mass damper (ACTMD) is proposed. An ACTMD is a semiactive dynamic vibration absorber by which the undesirable rotational vibrations of a structure can be greatly suppressed. It can also be used to attenuate translational vibrations that are converted into rotation by means of an appropriate mechanism. Retuning the absorber with the instantaneous excitation frequency is accomplished by changing the configuration of the ACTMD. The device consists of both fixed and moving parts. To readjust the absorber with the new condition, the position of the moving parts should change. As a result, the device’s mass moment of inertia (MMI) alters and the ACTMD adapts to the new condition in real time. However, the device may not cover all frequency bands, because the moving parts cannot be located in all desirable places. After determining the governing equations, the other effects of alternation in the device’s configuration, such as the attenuation-amplification coefficient, are interpreted. Then, the performance of the absorber is evaluated by controlling a transient rotational vibration through numerical simulation. Finally, a sensitivity analysis is carried out to identify a suitable range of MMI for designing an ACTMD.