Catastrophe in Fault Developing Process of Rotor System

Characteristics and geometrical description of catastrophic fault and the formation mechanism of faults occurred in mechanical system are introduced and analyzed. Mathematic descriptions are given to catastrophic faults especially in the state of system vibration based on nonlinear and catastrophe theories. The equations of a bifurcation set are derived, by which a critical value for catastrophic amplitude is obtained. When an excitation amplitude exceeds the critical value, a catastrophe will occur in the state of system vibration. So, the critical value can be used to diagnose and forecast the catastrophe phenomena in a mechanical system in order to restrain the occurrence and development of fault with effective measures taken.