Rotating dynamic absorber with viscoelastic element

Rotating machines operating at super-critical speeds must cross the critical speeds during run-up. Such situation is not always favorable considering the high vibration levels of the machine during resonance crossing. Considering that critical speeds do not change significantly during machine life time, one can think of employing vibration dynamic absorbers in the rotating element of the machine to tackle the problem of resonance crossing. In this work, a rotating dynamic absorber with viscoelastic element is designed for reducing machine response in its first critical speeds. The system is modeled by finite elements and the absorber design is tuned as a function of the thickness of the viscoelastic layer and of the thickness of the inertia ring. In the numerical results, a significant reduction of the resonance peaks is observed in the first critical speeds of the system when the absorber is employed. Such results allow the rotating system to operate super-critically in a smooth run-up.