Dynamic Analysis of a Hybrid Squeeze Film Damper Mounted Rub-Impact Rotor-Stator System

Abstract

An investigation is carried out on the systematic analysis of the dynamic behavior of the hybrid squeeze-film damper (HSFD) mounted a rotor-bearing system with strongly nonlinear oil-film force and nonlinear rub-impact force in the present study. The dynamic orbits of the system are observed using bifurcation diagrams plotted using the dimensionless rotating speed ratio as control parameters. The onset of chaotic motion is identified from the phase diagrams, power spectra, Poincaré maps, bifurcation diagrams, maximum Lyapunov exponents, and fractal dimension of the rotor-bearing system. The dynamic behaviors are unlike the usual ways into chaos ($1T\Rightarrow 2T\Rightarrow 4T\Rightarrow 8T\Rightarrow 16T\Rightarrow 32T\cdots \Rightarrow$ chaos or periodic $\Rightarrow$ quasi-periodic $\Rightarrow$ chaotic), it suddenly gets in chaos from the periodic motion without any transition. The results presented in this study provide some useful insights into the design and development of a rotor-bearing system for rotating machinery that operates in highly rotating speed and highly nonlinear regimes.