Experimental and Computational Study of a Tuned Damper with Frictional Contacts

Turbomachinery blisks have very low damping and, for this reason, they require devices such as ring dampers to mitigate excessive vibrations. Ring dampers rely on the relative motion between a ringlike component and the blisk to dissipate energy by means of friction. Damper effectiveness is typically low due to the absence of relative motion between the damper and the blisk. Tuned mass dampers can mitigate the low relative motion and can be particularly effective when the forcing is narrowband. Tuned mass dampers transfer vibration energy from the host structure to the damper, where this energy can be dissipated by friction. These two features are particularly useful when the host structure has very low damping and when there are stringent constraints on the position of the damper, as is the case for turbomachinery blisks. In this paper, a tuned vibration damper concept is explored. A cantilever beam is used to represent a blisk blade. The vibration reduction provided by the use of a tuned mass damper with contacts is studied both computationally and experimentally. Numerical and experimental results are compared to validate the model and to gain insight into the energy dissipation phenomena and the working principles of such dampers.