Vibration analysis of distributed-lumped rotor systems Original Research Article

In this paper a distributed-lumped model for the analysis of the flexural vibrations of a rotor-bearing system is considered. A general formula for the determinant of the tri-diagonal partitioned matrix description of the system 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 method. The error source in the computation of the natural frequencies by the dynamic stiffness matrix method is discussed. It is shown that by implementing the transfer matrix method the natural frequencies obtained are of greater accuracy. A numerical example illustrating the two methods, is presented and the results achieved are commented upon.