Response evaluation of imbalance-rub-pedestal looseness coupling fault on a geometrically nonlinear rotor system

Yang, Yang; Yang, Yiren; Cao, Dengqing; Guo, Chen; Jin, Yulin

doi:10.1016/j.ymssp.2018.08.063

Cited by 66 publications

(22 citation statements)

References 37 publications

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“…Three different models of fatigue crack are widely adopted in the stability analysis of rotor system at present, namely, the open model, the switching model and the breathing model. The switching crack model believes that the transition of crack state is completed immediately and has many applications in rotor crack fault and dynamic parameter identification [9,10]. For the Machines 2021, 9, 79 2 of 14 large rotors running at low speed, crack state changes gradually during rotation.…”

Section: Introductionmentioning

confidence: 99%

Vibration and Stability Analysis of a Bearing–Rotor System with Transverse Breathing Crack and Initial Bending

Wang

Xiong

2021

Machines

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This paper focuses on the stability and nonlinear response of a bearing-rotor system affected by a transverse crack and initial bending which was thought to be part of an unbalance or had been neglected before. The differences of breathing functions for the transverse breathing crack caused by initial bending is presented here, and the calculation of time-varying finite elements stiffness matrix of the cracked shaft is improved by replacing traditional the approximate crack segment with an exact area. After establishing the dynamic model of the cracked rotor with initial bending, vibrational characteristics such as amplitude-speed diagram, frequency spectrogram and bifurcations are investigated in detail. The eigenvalues of the transition matrix are calculated and analyzed as an indicator of dynamic stability with the growths of crack depth and initial bending. Many differences are found between the two cases of dynamic response of rotor system by numerical simulation. The frequency change with the growth of initial bending is opposite to the change with the growth of crack depth, and the shapes of amplitude-speed also having great different features. Stable regions are reduced and extended laterally by initial bending. All these results obtained in this paper will contribute to identify the bending fault and assess the stability of the bearing-rotor systems.

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Section: Introductionmentioning

confidence: 99%

Vibration and Stability Analysis of a Bearing–Rotor System with Transverse Breathing Crack and Initial Bending

Wang

Xiong

2021

Machines

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“…Gas bearing rotor system more easily suffers from instability at high speed due to the inherently low damping and load capacity of gas film. 4,5 The residual unbalance, 6 bearing pedestal stiffness, 7 and localized defect of bearing 8 greatly affect the radial vibrations of rotor system, which may lead to the radial rub impact when the radial clearance is smaller than the vibration amplitude. Improper installation, thermal expansion, and axial force imbalance can even occupy the normal axial clearance, which leads to the axial rub impact of rotor with stator.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Investigation on Axial Rub Impact Dynamic Characteristics of Flexible Rotor Supported by Hybrid Gas Bearings

Long

Han

Zhao

et al. 2021

Journal of Low Frequency Noise, Vibration and Active Control

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Gas bearings are widely used in micro- and small turbomachinery. Because of the pursuit of high efficiency, turbomachinery adopts small clearance of rotor and stator. The gas bearing rotor system easily suffers from rub impact due to the inherently low damping and load capacity of gas film. Axial rub impact may lead to catastrophic failure of gas bearing rotor system. Previous work put emphasis on radial rub, and only a few papers researched on the axial rub impact by simulation method. In this paper, dynamic responses of full annular axial rub are investigated numerically and experimentally. A single span flexible rotor test rig is established to support this research. Dynamic characteristics of full annular axial rub of this gas bearing rotor system are obtained with finite element language-APDL. Dynamic characteristics within full speed range are experimentally researched based on the test rig. The dynamic behaviors are analyzed by means of waterfall diagrams, frequency spectrums, orbit trails, and vibration amplitude waveforms. During speed up, half speed whirl and gas film oscillation occur in radial direction. During speed down, the full annular axial rub between rotor thrust disk and gas bearing occurs. When lightly axial rub impact happens, the vibration patterns in the radial direction change barely, and 0 Hz component appears in the axial direction. When serious full annular axial rub impact happens, 0 Hz component occurs in both radial and axial directions and rotor orbit shows transverse motion in radial direction. These forms of dynamic characteristics can be effectively used to diagnose the full annular axial rub impact.

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“…Transient vibration behaviours of rotor systems are of great significance for the condition monitoring and dynamical investigations [1,2]. Darpe et al [3] investigated the transient responses of a cracked rotor and discussed the diagnosis of crack fault.…”

Section: Introductionmentioning

confidence: 99%

Response analysis of an accelerating unbalanced rotating system with both random and interval variables

Yang

et al. 2020

Journal of Sound and Vibration

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This paper investigates the accelerating up transient vibrations of a rotor system under both the random and uncertain-but-bounded uncertainties. The Polynomial Chaos Expansion (PCE) coupled with the Chebyshev surrogate method is used to analyses the propagations of the two categorizes of uncertainties. The output responses will possess the characteristics of both bounded quantities and statistical moments. As a hybrid non-intrusive uncertainty quantification (UQ) procedure, the deterministic rotor model is taken as a black box and will only be executed at specific parameter points. A number of uncertain physical parameters are studied and the corresponding transient responses are presented. The accuracy and efficiency are verified by the Monte Carlo simulations (MCS) in combination with the scanning scheme and also other hybrid analysis framework. It will provide guidance for the accurate transient dynamic analysis of engineering problems with hybrid uncertainties.

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Response evaluation of imbalance-rub-pedestal looseness coupling fault on a geometrically nonlinear rotor system

Cited by 66 publications

References 37 publications

Vibration and Stability Analysis of a Bearing–Rotor System with Transverse Breathing Crack and Initial Bending

Vibration and Stability Analysis of a Bearing–Rotor System with Transverse Breathing Crack and Initial Bending

Numerical and Experimental Investigation on Axial Rub Impact Dynamic Characteristics of Flexible Rotor Supported by Hybrid Gas Bearings

Response analysis of an accelerating unbalanced rotating system with both random and interval variables

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