Analysis of Vibration Characteristics of Rotor-Stator Rubbing Faults in a Dual-Rotor System

Studying rotor-stator rubbing faults in dual-rotor systems has significant engineering and practical value. This paper focuses on the vibration characteristics of dual-rotor systems under rotor-stator rubbing faults. Firstly, a dual-rotor system model incorporating a tapered beam structure is established based on the finite element method, and the corresponding dynamic equations are derived. Secondly, the blade-casing rubbing force model is applied to the dual-rotor system to investigate the vibration characteristics under rotor-stator rubbing faults. The Newmark-B method is used to solve the fault dynamic equations, exploring the impact of blade count and rubbing stiffness on the response. The accuracy of the simulation results is verified through experiments. The results indicate that, in rotor-stator rubbing faults, as the number of blades increases, the “hardening” effect of the rotor becomes significant, and the resonance speed point of the low-pressure rotor shifts significantly backward. As the rubbing stiffness increases, the vibration amplitude of the rubbed rotor decreases significantly at a constant speed, indicating that rotor-stator rubbing faults can be considered as a “constraint” effect on the rotor.