Abstract:Based on further study of multispan double rotor model establishment method and coupling model,by comprehensively considering centrifugal,rubbing and so on,the dualrotor system model was built,which included the parallel misalignment of coupling,the fleet angle misalignment of coupling and parallel misalignment angle comprehensive coupling.Variable step length fourthorder RungeKutta method was used to solve the nonlinear dynamic model of the biaxial rotorslide bearing system with misalignment.The Poincare crosssection diagram,axis trace diagram,waveform diagram,and spectrogram diagram were obtained to show the system’s state of motion in certain parameter domains.The bifurcation chart diagram and threedimensional spectrum diagram were analyzed to reveal the cycle,cycle times,pseudo cycles behavior and nonlinear dynamic phenomena of the rotor system,such as frequency oscillation,amplitude jump,quasiperiodic motion,chaos,etc.The results prove that the range of motion of rotor is increased,and the motion of rotor becomes more chaotic during exercise in this system,even seriously comprehensive misalignment fault will result in the chaos state of rotor system.The misalignment has a significant effect on the overall vibration of the rotor system.When the misalignment is more serious,the vibration pattern of the whole system is more complicated,and the simulation analysis results are in good agreement with the experimental results.