Finite element model of asymmetrical rotor-bearing systems

Recently, the finite element method (FEM) has been commonly applied in the engineering analysis of rotor dynamics. Gyroscopic moments, rotary inertia, transverse shear deformation and gravity can be included in computational models of rotor-bearing systems. In this paper, a finite element model and its solution method are presented for the calculation of the dynamics of dual rotor systems. A typical structure with two rotor shafts is discussed and the procedure for obtaining the coupling motion equations of the subsystems is illustrated. A computer program is developed to solve critical speeds and to simulate the transient motion. The influence of gyroscopic moments on co-rotation and counter-rotation is analyzed, and the effect of the speed ratio on critical speed is studied. The dynamic characteristics under different conditions of increasing speed during start-up are demonstrated by comparison with transient nodal displacements. The presented model provides a complete foundation for further investigation of the dynamics of dual rotor systems.

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“…According to the geometric analysis in Fig. 4, the slopes (B, Γ) can be given by the following relationships (Jei and Lee, 1988):…”

Section: Finite Shaft Elementmentioning

confidence: 99%

Investigation of the dynamic characteristics of a dual rotor system and its start-up simulation based on finite element method

Fei

Tong

Wei

2013

J. Zhejiang Univ. Sci. A

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“…Initially, Gladwell and Sammers (1966) presented governing equations of motion of asymmetric rigid rotor shaft. Jei and Lee (1988) extended the FEM for rotor-bearing frameworks including gyroscopic moment, rotary inertia and the effect of transverse shear which also counts for asymmetry. Further, impacts of boundary conditions and rotor asymmetry on the modal properties and stability were inspected by Jei and Lee (1992).…”

Section: Modelling Of Rotormentioning

confidence: 99%

A review on modelling and dynamic analysis of viscoelastic rotor systems

Ganguly

Chandraker

Roy

2022

AEAT

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Purpose The purpose of this study is to bring down collective information about various issues encountered in modelling of rotor systems. Design/methodology/approach The most important and basic part of “rotor dynamics” is the study related to its different modelling techniques which further involves the analysis of shaft for understanding the system potential, competence and reliability. The issues addressed in this study are classified mainly into two parts: the initial part gives out a vast overview of significant problems as well as different techniques applied to encounter modelling of rotor systems, while the latter part of the study describes the post-processing problem that occurs while performing the dynamic analysis. Findings The review incorporates the most important research works that have already placed a benchmark right from the beginning as well as the recent works that are still being carried out to further produce better outcomes. The review concludes with the modal analysis of rotor shaft to show the importance of mathematical model through its dynamic behaviour. Originality/value A critical literature review on the modelling techniques of rotor shaft systems is provided from earliest to latest along with its real-time application in different research and industrial fields.

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“…The accidental or intended presence of asymmetry (rotating asymmetry) in a rotor system, which may be caused by the rotating machine failures, may significantly alter its dynamic characteristics, such as the unbalance response, critical speeds and stability, from those of the ideal isotropic (symmetric) rotor (Jei and Lee, 1988). Thus, the complex modal testing theories and methods have been extensively developed to accurately identify the asymmetric properties and understand the dynamic behavior of practical rotors (Lee, 1991;Lee, 1993).…”

Section: Directional Frequency Response Functionsmentioning

confidence: 99%

Complex modal testing of asymmetric rotors using magnetic exciter equipped with hall sensors

Lee

Kim

2001

KSME International Journal

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The complex modal testing methods developed for asymmetric rotors are briefly discussed and their performances are experimentally evaluated. For the experiments, a laboratory test rotor is excited by using a newly developed, cost effective magnetic exciter equipped with Hall sensors, which measure the excitation forces. It is concluded that the exciter system is characterized by a wide bandwidth and a high resolution for both the excitation and force measurement, and that the one-exciter/two-sensor technique for complex modal testing of asymmetric rotors is superior to the standard two-exciter/two-sensor technique in terms of practicality and realization.

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Finite element model of asymmetrical rotor-bearing systems

Cited by 15 publications

References 18 publications

Investigation of the dynamic characteristics of a dual rotor system and its start-up simulation based on finite element method

Investigation of the dynamic characteristics of a dual rotor system and its start-up simulation based on finite element method

A review on modelling and dynamic analysis of viscoelastic rotor systems

Complex modal testing of asymmetric rotors using magnetic exciter equipped with hall sensors

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