Dynamic simulation and experimental study of dual-rotor system induced by rub-impact fault with variable state and parameter

Abstract A dynamic modeling method of dual-rotor system is proposed according to the structure feature and the rub-impact fault with variable state and parameter. The interactional mechanism of different parameters on the dual-rotor system is disclosed in this dynamic model, where multiple parameters are considered including of stator stiffness, eccentricity, static clearance, friction factor, radial clearance of intermediate bearing and contact effect between rotors. The vibrational responses of dual-rotor system with rub-impact are derived by numerical simulation. The dynamic characteristics for this system without faults and under rub-impact faults are analyzed by means of time domain diagram, spectrum diagram, axis locus diagram, bifurcation diagram and Poincare cross section diagram. And the dual-rotor test bench is established, and the dual-rotor trouble-free, mild and severe rub-impact failure experiments are carried out. Comparisons between experimental results and simulation analyses are conducted to validate the correctness of the theoretical model. The research results offer theoretical guidance for the structural design and the diagnosis of rub-impact fault of dual-rotor system.