Dynamic Characteristic Analysis Of A Rotor System With Titanium Alloy Impeller Rub-impact Of Centrifugal Air Compressors

Aiming on the failure of the titanium alloy impellers of centrifugal air compressor,this thesis takes the rubbing between the impeller and the casing as the studying objects. The research is based on the physical&mathematical model and the numerical simulation of finite element method.According to the research on the basic behavior and mathematical model of rubbing process, the solutions of the rubbing contact, friction heat and heat transfer are proposed. Constructing the geometric model and finite element model of the rubbing process of impeller and casing are established. The stress and strain of contact zone under the different contact loading are computed, and the stress and strain distribution are analyzed as the impeller in high-speed rotation is rubbing with the casing. The relationship curves of the heat and temperature of the impeller with rotational speed under the different loading conditions are obtained.The temperature field, and the relation of the maximum temperature and the rotating speed in contact zone are gotten. Basis on the analysis of the physical model of the impeller rotor system, the geometric model and finite element model of impeller rotor system are constructed, the natural frequency is analyzed and calculated, and the motion behaviors of unbalance response and rubbing process of the rotor system are investigated. The influence of the unbalanced load caused by the rotor mass eccentricity on the motion behavior of rotor system is studied, and the behavior of the rotor under the contact force is researched when the impeller is colliding with the stator casing.The results of this thesis about the failure mechanism of centrifugal air compressor titanium alloy impeller analysis provide a theoretical basis for rotor system design.