Nonlinear dynamic analysis and experimental verification of a magnetically supported flexible rotor system with auxiliary bearings

Ebrahimi, Reza; Ghayour, Mostafa; Khanlo, Heshmatallah Mohammad

doi:10.1016/j.mechmachtheory.2017.11.018

Cited by 31 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is a continuation of work presented in Ref. 13, where the mathematical modeling of system was discussed and the influences of rotating speed and backup bearings stiffness were analyzed.…”

Section: Introductionmentioning

confidence: 63%

Experimental and theoretical investigations of unbalance flexible rotor in active magnetic bearings considering backup bearings contacts

Ebrahimi

2022

Noise & Vibration Worldwide

Self Cite

View full text Add to dashboard Cite

This paper describes the experimental verification of an unbalance flexible rotor model in active magnetic bearings. The dynamic modeling takes into account the gyroscopic moments of the disk, geometric coupling of the magnetic actuators, and contact forces of the backup bearings. The Rung–Kutta method is used to integrate the equations of motion. The nonlinear dynamic response is analyzed using bifurcation plots, disc center trajectories, Fast Fourier Transforms, Poincaré maps, and maximum Lyapunov exponent. The analysis is carried out for different values of rotating speed and unbalance eccentricity. In the unbalance test, a concentrated mass of 5 gr is attached in three radial position of the disk. The numerical simulations and experiments prove that a variety of nonlinear dynamical phenomena such as period -3, -4, -8, periodic, quasi-periodic, and chaotic motions occur in the system. The results indicate that the response of the rotor returns back to a regular motion by increasing the rotational speed. Also, by increasing the unbalance eccentricity, the first irregular motion initiates at much higher rotational speeds. Therefore, sufficient attention should be paid to these factors in design of a flexible rotor system equipped with both active magnetic bearings and backup bearings in order to ensure system reliability.

show abstract

Section: Introductionmentioning

confidence: 63%

Experimental and theoretical investigations of unbalance flexible rotor in active magnetic bearings considering backup bearings contacts

Ebrahimi

2022

Noise & Vibration Worldwide

Self Cite

View full text Add to dashboard Cite

show abstract

“…Extensive recent research has been carried out on exploring, both experimentally and through mathematical models, the nonlinear vibrational dynamics of rotating machines, see e.g. [2,3,4,5,6] and references therein for recent developments. The typical mechanisms that allows energy transference to vibration modes from the rotating mass is the presence of centrifugal forces due to out-of-balance or out-of-alignment eccentricity.…”

Section: Literature Review Of Nonlinear Problems In Rotodynamicsmentioning

confidence: 99%

Characterising Spectral Anomalies in Rotating Machine Sensors

Champneys

Aitken

Alecio

et al. 2021

Preprint

View full text Add to dashboard Cite

Several spectral analysis algorithms have been developed to identify spectral anomalies. A careful literature analysis is undertaken of sources of nonlinearity through bearing distress and other contacts and rubs within rotor dynamics. Several different models for such contact-force or lubrication nonlinearities are synthesised from the literature. These forces are implemented within a simulation of a simple Jeffcott rotor. Reasonable parameter values are identified and results are reproduced that are qualitatively similar to both those observed by Faraday Predictive and seen in the literature. The results enable a tentative hypothesis, using the theory of Arnold tongues, about how the severity of bearing distress may be reflected in changes to the observed spectrum. Various recommendations are made as to avenues of further work to hone the algorithms, apply spectral analysis to the synthetic simulation data, and to perform more systematic parameter studies.

show abstract

“…4,5 Those errors in ABMS affect the machining productivity and quality of the workpiece surface. Therefore, many scholars have studied the dynamic properties of ABMS, 6–8 and they have also made many achievements in the spindle system. Indeed, there are still many problems with the spindle system, which need to be studied deeply, and these problems also play important roles in the machining performance, which obviously could reduce machining accuracy.…”

Section: Introductionmentioning

confidence: 99%

Theoretical prediction and experimental verification of the unbalanced magnetic force in air bearing motor spindles

Sun

Chen

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part B:

View full text Add to dashboard Cite

Dynamic vibrations of air bearing motor spindles have significant influence on the surface quality in ultra-precision machining. In this article, the influence of the vibration caused by the unbalanced magnetic force on the diamond turning is investigated on the basis of the theoretical and experimental method. A permanent magnet motor model (10 poles and 12 slots) is built and then simulated to gain a periodic unbalanced magnetic force. The effects of unbalanced magnetic force on the inclination of the spindle shaft is analyzed, which would affect the surface quality of the workpiece, and the surface topography of the workpiece is predicted during an unbalanced magnetic force acting on air bearing motor spindle. The theoretical analysis and experimental turning results validate that the angle between the direction of unbalanced magnetic force and the feed direction has a certain relationship with the profile of the machined surface. Also, under different turning speeds and directions, the surface topography of the machined workpiece shows a 10-cycle-per-revolution pattern, which has good agreement with the simulations of periodic unbalanced magnetic force. This research work provides a theoretical foundation for the fault diagnosis of air bearing motor spindle caused by motor rotor eccentricity and its effect on surface generation in turning.

show abstract

Nonlinear dynamic analysis and experimental verification of a magnetically supported flexible rotor system with auxiliary bearings

Cited by 31 publications

References 10 publications

Experimental and theoretical investigations of unbalance flexible rotor in active magnetic bearings considering backup bearings contacts

Experimental and theoretical investigations of unbalance flexible rotor in active magnetic bearings considering backup bearings contacts

Characterising Spectral Anomalies in Rotating Machine Sensors

Theoretical prediction and experimental verification of the unbalanced magnetic force in air bearing motor spindles

Contact Info

Product

Resources

About