The Impact of Squeeze Film Damper and Support Nonlinear Forces on the Dynamic Response of High-Speed Flexible Rotors

To investigate the nonlinear dynamic response of rotor systems, a finite element model of the squeeze film damper-rotor system was established. With the Euler–Bernoulli beam rotor model, the nonlinear oil film forces of the squeeze film damper (SFD) and the nonlinear restoring forces of the supports are applied as external loads to the support nodes using the finite element method. The Newmark Beta method was used to solve it, and the nonlinear dynamic response of the rotor was analyzed using frequency–response curves, time-domain response diagrams, and shaft centerline trajectory diagrams. The effects of different oil film gaps and support restoring force coefficients on the rotor response were examined. The results show that the coupling effect of the two nonlinear forces is the superposition of their individual effects; the two nonlinear forces have a significant impact on the rotor response amplitude, and appropriate parameter selection and installation positions can reduce the amplitude by 19%; and finally, among the two nonlinear forces, the SFD nonlinear oil film force mainly affects the amplitude, while the support nonlinear restoring force affects both the amplitude and frequency.