Rub-Impact Investigation of a Single-Rotor System Considering Coating Effect and Coating Hardness

Abstract

Rub-impact of rotor–stator is one of the major problems for stability and safety of a rotating machine. As a result, the characterization of rub-impact force gradually becomes a crucial factor in the dynamic responses prediction of the rotor system. First, the applicable scope of classical rotor–stator rub-impact force models is discussed in this paper. Then, taking a Jeffcott rotor as the research object, rub-impact force models under hard coating, soft coating and general condition are established respectively based on the equivalent linearized method. Finally, dynamic responses of the rotor system are numerically calculated by the linear interpolation method, and the change laws of impact stiffness are further analyzed under different conditions. Then, the effects of the engine coatings on the dynamic characteristics of the rotor system are studied in detail. By means of bifurcation diagram, time histories, whirling orbits, spectrum and impact force diagram, the dynamic variations are revealed. The results suggest that the dynamic responses of system are closely related to the coating hardness. Meanwhile, the full annular rub and partial rub are affected by the coating hardness to a great extent.