The rotor system often operates in the harsh conditions of high speed, temperature and pressure and its force is very complex. The dynamics model of the rotor system with multi degree of freedom was established by using the finite element method. The vibration modes and the effect of rotor support stiffness on critical speed of the rotor system were studied. Moreover, the comparisons of unbalance response in considering and ignoring the complex temperature for the rotor were employed. The results show that he rotor system response amplitude increased significantly when the complex the temperature field is considered. With the start-up time increases, the amplitudes of the rotor system are gradually increased. When the start time exceeds 15 s, the amplitude is increased almost linearly.

 

Rotor system is an important device in petrochemical equipment units and there is a non-normal phenomena of big vibration in it. Based on the finite element method, the model of the dynamics characteristics of a rotor system was set up, and problems such as critical speeds and steady imbalance response were calculated. The effect of imbalance distribution on rotor dynamics characteristics was studied and the parameters affecting the dynamics characteristics of the rotor system were found out. This provides a theoretical basis for fault diagnosis and resolution of rotor system.

Based on nonlinear dynamic properties, the dynamic model of two-span sliding bear-rotor with coupling nonlinear oil and rubbing force were studied by means of numerical stimulation. The effect of oil and rubbing force on bifurcation and chaos behaviors is analyzed. Abundant dynamic behaviors of rotor were revealed by the diagrams displaying bifurcation and chaos behaviors, such as Poincaré mapping, bifurcation diagram, phase plane plots, locus trajectory, as well as amplitude spectrum. The results show that the system of bearing-rotor with nonlinear impact/rub and oil film force has abundant nolinear dynamic behaviors.