Nonlinear Dynamic Response Analysis of Rotor-Ball Bearing-Stator Coupling System Including Unbalance-Rubbing Coupling Faults

2007 ◽  
Author(s):  
Guo Chen ◽  
Rong Tao Hou
Keyword(s):  
Ball Bearing ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Nonlinear Dynamic Response ◽  
Rotating Speed ◽  
Coupling Faults ◽  
Mass Unbalance ◽  
Coupling System ◽  
Chaos Motion ◽  
Rotor Mass

In this paper, a new rotor-ball bearing-stator coupling system dynamic model is established. In the model, the rotor mass unbalance and rubbing faults are included, and the nonlinear factors of ball bearing such as the clearance of bearing, nonlinear Hertzian contract force between balls and races, and the varying compliance vibration coming from the periodical variety of contact positions between balls and races are modeled. The numerical integral method is employed to obtain system’s responses, and the vibration amplitude-rotating speed curve, bifurcation plot, phase plane plot, shaft centre orbits, frequency spectrum and Poincare´ map are used to carry out the analysis of bifurcation and chaos motion, and the effects of rotational speed, rubbing stiffness, rotor eccentricity, bearing house-stator stiffness, and stator-foundation stiffness on dynamic responses are analyzed, and the non-linear dynamic characteristics of rotor-ball bearing-stator system under unbalance and rubbing coupling faults are discovered.

Interaction of a Whirling Rotor with a Vibrating Stator across a Clearance Annulus

1968 ◽  
Vol 10 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. F. Black
Keyword(s):  
Dry Friction ◽  
Ball Bearing ◽  
Radial Symmetry ◽  
Experimental Results ◽  
Equilibrium Conditions ◽  
General Behaviour ◽  
Mass Unbalance ◽  
Jump Phenomena ◽  
Rotor Stator Interaction ◽  
Rotor Mass

Where a rotor runs within a clearance space, the clearance being comparable with rotor mass unbalance, the synchronous whirling behaviour of the rotor may be considerably affected by intermittent interaction with the stator at the clearance position. Discontinuity and jump phenomena may occur: in general, behaviour will be different with increasing speed from that with decreasing speed, and in either case zones may exist in which rotor-stator interaction is possible but not certain. In the analysis here presented, rotor and stator are regarded as linear multi-degree-of-freedom systems including damping; dry friction at the clearance space is taken into account. Discussion is limited to cases with radial symmetry, and interaction is assumed limited to the position of the clearance space. Polar receptances are used to establish equilibrium conditions with interaction, and speed zones are defined within which interaction may occur. Some hypothetical cases are fully explored, demonstrating that rotor-stator interactions may occur in a variety of forms and circumstances. Interactions with dry friction counterwhirling are also considered. Some experimental results on counterwhirl within a ball bearing are given and qualitatively compared with theory.

Dynamic Analysis of Flexible Rotor-Ball Bearings System with Unbalance-Misalignment-Rubbing Coupling Faults

2011 ◽  
Vol 105-107 ◽  
pp. 448-453 ◽  
Author(s):  
Jun Hong Zhang ◽  
Liang Ma ◽  
Jie Wei Lin ◽  
Gui Chang Zhang
Keyword(s):  
High Frequency ◽  
Ball Bearing ◽  
Frequency Component ◽  
Sine Wave ◽  
Dynamic Responses ◽  
High Frequency Component ◽  
Element Analysis ◽  
Frequency Wave ◽  
Coupling Faults ◽  
Bearing System

Dynamic responses of flexi rotor-ball-bearing system under unbalance misalignment rubbing coupling faults are studied. Coupling faults dynamic control model of flexi-multi-system of rotor-ball-bearing system is established, based on finite element analysis and numerical integral combined simulate method. Then nonlinear bearing force and rub-impact force models are programmed in MATLAB. Analysis and compare vibration characteristics of system while under faults-free, unbalance and rub-impact faults. The result demonstrates that when system under unbalance faults, vibration frequency brought by eccentric mass is agreed with rotating speed frequency, its fundamental frequency wave add high frequency component, can show the characteristics of unbalance-rubbing faults efficiently; when system under misalignment faults, with frequency double vibration and high harmonics; when system under unbalance-misalignment-rubbing coupling faults, support force of shafting of rotor system appears high frequency responses like saw tooth based on sine wave, causing aggravation of rub-impact faults.

Nonlinear Dynamic Analysis and Experiment Verification of Rotor-Ball Bearings-Support-Stator Coupling System for Aeroengine With Rubbing Coupling Faults

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
G. Chen ◽  
C. G. Li ◽  
D. Y. Wang
Keyword(s):  
Nonlinear Dynamic Analysis ◽  
Coupling Model ◽  
Hertzian Contact ◽  
Squeeze Film ◽  
Ball Bearings ◽  
Rotating Speed ◽  
Coupling Faults ◽  
Coupling System ◽  
Experiment Verification ◽  
Effect Of Support

In this paper, a new rotor-ball bearings-support-stator coupling system dynamic model with rubbing coupling faults is established for practical aeroengine. In the model, the rubbing fault is modeled, the stator motion is considered, the flexible support and squeeze film damper are established, and the nonlinear factors of ball bearing, such as the clearance of the bearing, the nonlinear Hertzian contact force between balls and races, and the varying compliance vibration because of the periodical variety of the contact position between balls and races, are modeled. The numerical integral method is used to obtain the system responses, the effect of support stiffness on rotor responses is studied using a vibration amplitude-rotating speed plot, and the characteristics of the rubbing fault is analyzed using a 3D cascade plot. An aeroengine tester with a stator is established to carry out the rubbing fault experiments, the simulation results from the rotor-ball bearings-support-stator coupling model are compared with the experimental results, and the consistency of the results show fully the effectiveness of the new rotor-ball bearings-support-stator coupling model with rubbing fault.

Study on Nonlinear Dynamic Response of an Unbalanced Rotor Supported on Ball Bearing

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
G. Chen
Keyword(s):  
Nonlinear Dynamic ◽  
Ball Bearing ◽  
Period Doubling ◽  
Dynamic Responses ◽  
Hertzian Contact ◽  
Frequency Spectra ◽  
Rotating Speed ◽  
Unbalanced Rotor ◽  
Motion Period ◽  
Contact Position

An unbalanced rotor dynamic model supported on ball bearings is established. In the model, three nonlinear factors of ball bearing are considered, namely, the clearance of bearing, nonlinear Hertzian contact force between balls and races, and the varying compliance vibrations because of periodical change in contact position between balls and races. The numerical integration method is used to obtain the nonlinear dynamic responses; the effects of the rotating speed and the bearing clearance on dynamic responses are analyzed; and the bifurcation plots, the phase plane plots, the frequency spectra, and the Poincaré maps are used to carry out the analyses of bifurcation and chaotic motion. Period doubling, quasiperiod loop breaking, and mechanism of intermittency are observed as the routes to chaos.

scholarly journals Vibration characteristics of triple-gear-rotor system in compressed air energy storage under variable torque load

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098705
Author(s):  
Xinran Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xuehui Zhang ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Element Model ◽  
Rotor System ◽  
Dynamic Responses ◽  
System Response ◽  
Rotating Speed ◽  
Torque Load ◽  
Set Up ◽  
Two Stages

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.

Parameters research on time-varying stiffness of the ball bearing system without race control hypothesis

2021 ◽  
pp. 095440622110179
Author(s):  
Yongzhen Liu ◽  
Yimin Zhang
Keyword(s):  
Ball Bearing ◽  
Combined Loading ◽  
Time Varying ◽  
Noticeable Effect ◽  
Rotating Speed ◽  
Bearing Stiffness ◽  
Vibration Mechanism ◽  
Control Hypothesis ◽  
Full Consideration ◽  
Bearing System

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson (N-R) method with dynamic declined factors is presented. The effect of the dispersion of bearing parameters and the installation errors on the time-varying carrying characteristics of the ball-raceway contact and the bearing stiffness are investigated. Numerical simulation illustrates that besides the load and the rotating speed, the dispersion of bearing parameters and the installation errors have noticeable effect on the ball-raceway contact load, ball-inner raceway contact state and bearing stiffness, which should be given full consideration during the process of design and fault diagnosis for the rotor-bearing system.

Estimation of bridge static response and vehicle weights by frequency response analysis

1998 ◽  
Vol 25 (4) ◽  
pp. 631-639 ◽  
Author(s):  
G Thater ◽  
P Chang ◽  
D R Schelling ◽  
C C Fu
Keyword(s):  
Dynamic Effect ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Static Response ◽  
Actual Weight ◽  
Service Testing ◽  
Weigh In Motion ◽  
Moving Vehicles ◽  
Bridge Structures ◽  
Truck Weight

A methodology is developed to more accurately estimate the static response of bridges due to moving vehicles. The method can also be used to predict dynamic responses induced by moving vehicles using weigh-in-motion (WIM) techniques. Historically, WIM is a well-developed technology used in highway research, since it has the advantage of allowing for the stealthy automatic collection of weight data for heavy trucks. However, the lack of accuracy in determining the dynamic effect in bridges has limited the potential for its use in estimating the fatigue life of bridge structures and their components. The method developed herein amends the current WIM procedures by filtering the dynamic responses accurately using the Fast Fourier Transform (FFT). Example applications of the proposed method are shown by using computer-generated data. The method is fast and improves the predicted truck weight up to 5% of the actual weight, as compared to errors up to 10% using the current WIM methods.Key words: weigh-in-motion, digital filters, FFT, bridge dynamics, in-service testing.

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