Study On Dynamics And Nonlinear Vibration Of Rotor With Rubbing

The large turbine generator set, gas turbine, aviation engines, compressors and other rotating machinery are widely used and playing a very important role in the electric power, transportation, petrochemical industry which is closely related to people. The electric power, transportation, petrochemical industry is closely related to people’s field is widely used and plays a very important role. The stability of the rotor will determine the mechanical work properly, because the rotor system is the core part of large rotating machinery. The large turbo-generator set is important and precise rotating machinery, but the rotor system often have faults by the work environment is very complex and the influences of errors of manufacture, installation. In order to reduce the gas consumption and heat consumption rate of steam turbine unit, the probability of the rubbing fault is increases by the gap between rotor and stator is decreases of steam turbine. Moreover, rubbing faults will affect the normal work of steam turbine, caused great economic losses and security threats for enterprises and staff. So the researches of nonlinear vibration characteristics of a rotor system with rubbing fault, not only has very important academic value, but also has great significances for the safe running of the national economy and people’s normal life.In this paper, the actual steam turbine rotor is simplified to the physical model with lumped mass Jeffcott rotor, using the theory of nonlinear vibration analysis such as bifurcation phenomenon, mutation phenomenon, and chaotic phenomena to research the system dynamics model of the rotor with radial rubbing fault, quality eccentric force and nonlinear oil film force depthly. Then using the fourth order Runge kutta numerical simulation method to analyze the nonlinear dynamic behaviors of rotor system. Through the application of nonlinear methods such as bifurcation diagram, phase diagram, Poincare section, axis path diagram, found that rich nonlinear behaviors of system contain periodic, quasi-periodic and chaotic dynamics. In addition, the nonlinear behavior evolution process of system included period-doubling bifurcation and period-doubling bifurcation and so on. Discuss the influences of system parameters such as nonlinear friction coefficient and nonlinear stiffness coefficient, the oil film force parameters and foundation and asymmetric stiffness coefficient, eccentric direction angle of double span rotor disk to system finally.