Modeling of complex rotor systems by combining rotor and substructure models

Abstract Rotor systems have several unique characteristics in comparison to other dynamic systems, especially gyroscopic effects in rotating portions, non-symmetric matrix terms, and properties which are functions of speed or frequency. This paper describes an approach which combines the capabilities of a general-purpose program with a program specifically addressing design of rotor systems. The approach involves modeling the non-rotating portions in terms of a superelement/substructure. This linear symmetric representation in the form of the reduced matrices is introduced into the rotor system program, and combined with conventional (but possibly non-symmetric) finite element matrices of the rotating components, bearings, and destabilizing effects.