Crack fault of rotor is one of the most prominent problems faced by magnetic bearing rotor system. In order to improve the safety performance of this kind of machinery, it is necessary to research the vibration characteristics of magnetic bearing cracked rotor system. In this paper, the stiffness model of the crack shaft element was established by the strain energy release rate (SERR) theory. T...

In order to have fault identification for the gate rotor shaft with multiple cracks effectively, the quantity identification method of the gate rotor shaft with multiple cracks based on wavelet finite element method is established and the frequency test of the gate rotor shaft based on blind source separation algorithm is analyzed. Firstly the wavelet finite element was established by combining...

A mathematical model of a cracked rotor and an asymmetric rotor with two disks representing a turbine and a generator is uti­ lized to study the vibrations due to imbalance and side load. Nonlinearities typically related with a “breathing” crack are included using a Mayes steering function. Numerical simulations demonstrate how the variations of rotor parameters affect the vibration response an...

To further enhance the early diagnose precision and efficiency for rotor crack under condition of strongly noise, AE signals is applied to extract fault feature of early rotor cracks with the advantages of strong anti-noise ability, clear fault feature. Based on the Pseudo Wigner-Ville Distribution (PWVD), the amplitude and frequency as feature vector are extracted from the AE signal in this pa...

Multifractal analysis has been used to diagnoze cracked and healthy rotors. Is has been shown that the complexity and regularity criteria of the dynamical systems defined by the multiple scaling of the time series can indicate the damages of the rotating shaft.

In this paper, we use the hybrid h-p version of the finite element method to study the effect of an open transverse crack on the vibratory behavior of rotors, the one-dimensional finite element Euler-Bernoulli beam is used for modeling the rotor, the shape functions used are the Hermite cubic functions coupled to the special Legendre polynomials of Rodrigues. The global matrices of the equation...

The rotors at Aratiatia have historically experienced cracking during service. The strains on a cracked rotor have recently been measured using a UHF strain gauge telemetry system to determine the effects of operating conditions upon the stress levels, which are responsible for crack initiation and growth. The strains were monitored on the web and skirt of the rotor, during cold and warm starts...

The dynamics and diagnostics of cracked rotors have been gaining importance in recent years. The present work deals with the detection of crack in rotor system and determination of crack parameters i.e. position of crack, depth of crack using Artificial Neural Networks (ANN). The detection of crack is based on the continuous wavelet transform (CWT) plots with 1/3 and 1⁄2 critical peaks as the c...