Study on the effect of dynamic stiffness of supporting structure on dynamic characteristics of the rotor system

The rotor systems are the critical components of many rotational machines. The dynamic stiffness of the supporting structure affects the dynamic characteristics of the rotor system significantly. The effect can’t be overlooked for obtaining accurate dynamic characteristics. The judgment index of dynamic stiffness influence (DSI) is proposed in this paper to evaluate the degree of dynamic stiffness influence on the dynamic characteristics. The dynamic model of the rotor system considering the dynamic stiffness of supports is established, and the expression of DSI is given. Then the Campbell diagrams and corresponding DSI values for different system parameters under the influence of dynamic stiffness are discussed and analyzed. The effectiveness of DSI is verified by the literature. Besides, an experiment is carried out to verify the effectiveness of the DSI. The results indicate that the effectiveness of DSI can be confirmed by both numerical and experimental cases, and that the DSI can evaluate the degree of dynamic stiffness influence well.