Dynamic analysis of touchdown bearing system integrated with ribbon damper

Abstract

This study theoretically evaluates the nonlinear transient response of rotors dropping onto Touch-Down Bearings (TDBs) when an unpredicted Active magnetic bearing (AMB) failure occurs. The TDB is typically composed of ball bearings, which provide stiffness to the system, and an additional ribbon damper is placed between TDB and housing to provide damping to the overall system. This paper aims to develop, simulate and analyse a mathematical Finite Element (FE) model based on modelling a dry friction ribbon damper that exhibits dry friction behaviour. It is modelled using the generalized Dahl and Lugre model to capture microslip behavior and the Stribeck effect. Rotor drop simulations are carried out by using the finite element method (FEM) with two of those dynamic friction models in the time domain. The numerical results show these models effectively reproduce energy dissipation and stabilize rotor trajectories by flattening rebounds. It proves that both the friction models performed well in providing sufficient damping to the system to save the TDBs from a catastrophic failure. A future work on validating the numerical result by doing an experimental work is suggested as they provided more damping while the real ribbon damper might not provide.