Vibration analysis of distributed-lumped rotor systems

In this paper a distributed-lumped model for the analysis of the flexural v ibrations of a rotor-bearing system is considered. A general formula for th e determinant of the tri-diagonal partitioned matrix description of the sys tem is derived. This enables the irrational characteristic determinant of, the system model to be obtained by the dynamic stiffness matrix method. The results obtained are compared to those acquired from the transfer matrix m ethod. The error source in the computation of the natural frequencies by th e dynamic stiffness matrix method is discussed. It is shown that by impleme nting the transfer matrix method the natural frequencies obtained are of gr eater accuracy. A numerical example illustrating the two methods, is presen ted and the results achieved are commented upon. (C) 2000 Elsevier Science S.A. All rights reserved.