Stability analysis of high speed lab centrifuges considering internal damping in rotor-shaft joints

Rotors of high speed lab centrifuges are often removable to enable the use of different rotors for one single drive. The removable rotor shaft connection is the main reason for internal damping leading to self excited vibrations. In this paper different models of internal damping are investigated. The main influence parameters for stability are deduced analytically and numerically. The numerical simulations were carried out with the simulation tool FERAN. It was developed by the authors and is introduced in this paper. The primarily objective of the paper is to demonstrate instability effects which could occur in real lab centrifuges and which could be hardly simulated by a simple 4 or 8 degree of freedom model of a Jeffcot rotor.