Researching On The Nonlinear Dynamics Of Rub-impact Rotor System By Numerical Simulation

Rotor system with rub-impact is the most important component of rotary machinery, which plays an irreplaceable role in the field of industry. With the development of technology, rotating machinery is towards high-speed, light-weight, high load direction, so the rotating machinery needs higher requirements and also brings about more rotor system nonlinear problems, promoting the developments of nonlinear science and rotor dynamics.At present, most of the researchers have made a lot of researches on typical faults of rubbing, crack and loosen by using the theories of nonlinear rotor system and rotor dynamics, analyzing bifurcation and chaos behaviors of rotor, but mainly studying on single fault of rotor more and on coupling fault less, the actual existence of various coupling faults of rotor system have comprehensive effected on nonlinear behavior.The rotor system fault was studied from simply to deeply, firstly studying the influence of rotor system only with rub-impact condition without considering other rotor faults by the frequency ratio and the deflection; secondly studying the influence of rotor system with the rub-impact and crack coupling faults, considering material nonlinearity and oil film force by the crack depth, the deflection and the stiffness of the stator; lastly studying the influence of rotor system with the coupling faults of rub-crack-loosen by the crack depth, the stiffness of the stator and the stator base quality of rotor, dynamics equations was established to analyze the nonlinear characters. The method of dimensionless was used in different equations and4order Runge-Kutta method was used to numerical simulate different nonlinear equations, the bifurcation diagram, Poincare map, chart of axis orbit, time domain, frequency domain were used to analyze the influence of rotor response. Corresponding different nonlinear dynamic behaviors caused by three kinds rotor faults were analyzed, theoretical analyzing the reasons for the generated nonlinear characteristics, which provides a theoretical basis for further analyzing of the rotor faults.Finally, the main work was summarized in this paper and the insufficiency was putting forward in the research process, which were better for the future researching direction and provide failure research trends.