Study of the diagnostic features of a rotor with a transverse crack

With the aim of seeking the diagnostic features of a rotor crack, the dynam ic responses of a cracked rotor in the subcritical, trans-critical and supe r-critical regions of operation are investigated in this paper, based on th e analysis of the vibration signatures collected during the acceleration pr ocess. A few feasible methods based on the holo-spectral analysis technique are specially developed for investigating the transient vibration behaviou r of a cracked rotor in a more detailed way. The experimental results show that, because the Proposed methods provide much more detailed and distingui shable characteristics for diagnosis, they are really effective for capturi ng incipient transverse cracks in a rotor. Moreover, these methods are also generic and applicable to all high-speed rotating machines such as turbine s, generators, motors and pumps. In addition, the crack breathing behaviour in the super-critical region is fia-ther investigated by experiments, from which a new research subject is brought forward. This is very helpful for correctly understanding the vibration characteristics of a cracked rotor. T he research work in this paper makes a marked contribution for the detectio n of the incipient crack and has important significance for obviating catas trophic machine failures.