Nonlinear analysis of a dual-disk rotor system considering elastoplastic contact

The contact effect of disk interfaces has an important influence on the dynamic response of the gas turbine rotor system. In order to improve the accuracy of the contact model, this paper proposes a modified contact model for the full deformation stage based on verified experimental results by considering the influence of elastoplastic deformation, the experimental results and the theoretical results of contact model are compared. In order to simplify the modeling process of the contact interface, the equivalent material layer was introduced to establish the finite element model of the dual-disk rotor-bearing system, and the dynamic response of the rotor system was solved by the Newmark-β method. The validation of the proposed contact model is verified by comparing the time-domain waveform diagram. The dynamic characteristics of the rotor system under different preloads and speeds are analyzed. Results demonstrate that the contact model proposed in this paper can reflect the actual contact state accurately, a certain amount of preload will cause the appearance of multiple combined frequency components, such as fr-2fn, 3fr-4fn (fr is rotating frequency, fn is oil film oscillation frequency). The work provides a theoretical reference for contact effect modeling of rotor system, and has prospective application in gas turbines.