Underplatform Damper Dynamics Seminar

Abstract

Underplatform dampers (UPD) are commonly used in aircraft engines to mitigate the risk of high cycle fatigue failure of turbine blades. The working principle of an UPD is the frictional dissipation of energy via relative motion between to neighbouring blades and the damper. This can lead to significant vibration reduction, but at the same time, the coupling between the blades leads to strong shifts of the resonance frequencies, and the friction at the interface can lead to wear. An accurate knowledge of the damper behaviour is required during engine design to ensure reliable operation.

The Vibration UTC at Imperial College London has recently proposed a nonlinear modelling approach for UPDs, based on a detailed explicit damper model and accurate input parameter measurements. The methodology allows a detailed capture of the macroscale nonlinear mechanisms at play at the interface, accurate prediction of the nonlinear dynamic response of a bladed system, and integration into the computation of the dynamic response over the lifetime of the damper. The numerical research was supported by an experimental program that provided significant crucial understanding and allowed validation of the results. This talk will highlight the modelling approach for UPD, discuss the obtained experimental understanding, and introduce some of the currently ongoing research in the area.