Chaotic behavior of a rotor-bearing system with pedestal looseness

The modern nonlinear dynamical system theory is used to analyze the complicated motion of a simple rotor-bearing system with pedestal looseness at one support. Various forms of periodic, quasi-periodic and chaotic motions are discussed by using the rotating speed as the control parameter. In the orbits of quasi-periodic and chaotic motions the orientation of the orbits can be more clearly observed. The structures of the Poincare's maps for some periodic motions have slowly-varying characteristics and some of them show a kind of quasi-periodic motion under long time conditions. Some of the structures of Poincare's maps have bifurcation phenomenon as the time is increased. These complicated motion features of the system can be used to diagnose the fault of pedestal looseness.