The fractional dimension identification method of critical bifurcated parameters of bearing-rotor system

The stable problem of rotor system, seen in many fields, has been cared for more. Nowadays the reasons of most losing stability are caused by nonlinea r behaviors This presents higher requirements to the designing of motor sys tem : considering nonlinear elements, avoiding the unstable parameter point s or regions where nonlinear phenomena will be presented. If a family of ti me series of the unknown nonlinear dynamical system cart only be got ( may be polluted by noise), how to identify the change of motive properties at d ifferent parameters? In this paper, through the study of Jeffcott rotor sys tem, the result that using the figures between the fractional dimension of rime-serial and parameter can be gained, and the critical bifurcated parame ters of bearing-rotor dynamical system can be identified.