829 Study on Transient Vibration of Bladed Disk Passing through Resonance : Transient Response Analysis of Mistuned Bladed Disk

In the field of rotor dynamics, increased attention is being given to the transient response analysis of the rotor, since the effects of impact loading and vibrations of the rotor arising from blade loss can be studied by a time transient solution of the rotor system. As recent trends in rotating machinery have been directed towards lightweight, high-speed flexible rotors, the effect of flexibility on transient response analysis is becoming of increasing importance. In the present paper, a transient vibration analysis is carried out on a flexible-disk/flexible-shaft system or rigid-disk flexible-shaft system subjected to a sudden imbalance that is assumed to represent the effect of blade loss. To solve the basic equation governing a rotating flexible disk the Galerkin’s method is used, and the equation of motion of the rotor system is numerically solved by employing the Runge-Kutta-Gill’s method. Experiments were conducted on a model rotor having a blade loss simulator; the shaft vibrations were also measured. The validity of the anaytical results was demonstrated by comparison with the experimental results.

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Transient Vibration of High Speed Lightweight Rotor due to Sudden Imbalance

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; Process Industries; Technology Resources; General ◽

10.1115/82-gt-231 ◽

1982 ◽

Cited By ~ 1

Author(s):

M. Sakata ◽

T. Aiba ◽

H. Ohnabe

Keyword(s):

Transient Response ◽

High Speed ◽

Rotor System ◽

Response Analysis ◽

Transient Vibration ◽

Flexible Shaft ◽

Shaft System ◽

Flexible Rotors ◽

Transient Response Analysis ◽

Blade Loss

In the field of rotor dynamics, increased attention is being given to the transient response analysis of rotor, since the effects of impact loading and vibrations of rotor arising from blade loss can be studied by a time transient solution of the rotor system. As recent trends in rotating machinery have been directed towards light-weight, high-speed flexible rotors, the effect of flexibility on transient response analysis is becoming of increasing importance. In the present paper, a transient vibration analysis is carried out on a flexible disc-flexible shaft system or rigid disc-flexible shaft system subjected to a sudden imbalance that is assumed to represent the effect of blade loss. To solve the basic equation governing a rotating flexible disc the Galerkin’s method is used, and the equation of motion of the rotor system is numerically solved by employing the Runge-Kutta-Gill’s method. Experiments were conducted on a model rotor having a blade loss simulator; the shaft vibrations were also measured. The validity of the analytical results was demonstrated by comparison with the experimental results.

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Accurate Interpolation of the Dependency of Modal Properties on the Rotation Speed for the Transient Response Analysis of Bladed Disks

10.1115/gt2021-58982 ◽

2021 ◽

Author(s):

Jing Tong ◽

Chaoping Zang ◽

E. P. Petrov

Keyword(s):

Transient Response ◽

Rotation Speed ◽

Spectral Composition ◽

Forced Response ◽

Reference Points ◽

Mode Shapes ◽

Response Analysis ◽

Transient Vibration ◽

Bladed Disks ◽

Bladed Disk

Abstract During fast gas-turbine engine acceleration and deceleration the transient vibration effects in bladed disk vibration become significant and the transient response has to be calculated. In this paper an effective method is developed for efficient calculations of the transient vibration response for mistuned bladed disks under varying rotation speeds. The method uses the large-scale finite element modelling of the bladed disks allowing the accurate description of the dynamic properties of the mistuned bladed disks. The effects of the varying rotation speed on the natural frequencies and mode shapes of a mistuned bladed disk and its effects on the amplitude and the spectral composition of the loading are considered. The dependency of the modal characteristics on the rotation speed are based on the evaluation of these characteristics at reference points followed by the interpolation to obtain values at any rotation speed from the operating range. A new method has been developed for the interpolation of mode shapes while preserving the orthogonality and mass-normalization of the mode shapes. The method of mode shape interpolation is elaborated for tuned and mistuned bladed disks. The accuracy and efficiency of the method is demonstrated on test examples and on analysis of transient forced response of realistic bladed discs.

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Accurate Interpolation of the Dependency of Modal Properties On the Rotation Speed for the Transient Response Analysis of Bladed Disks

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4052501 ◽

2021 ◽

Author(s):

Jing Tong ◽

Chaoping Zang ◽

Evgeny Petrov

Keyword(s):

Transient Response ◽

Rotation Speed ◽

Spectral Composition ◽

Forced Response ◽

Reference Points ◽

Mode Shapes ◽

Response Analysis ◽

Transient Vibration ◽

Bladed Disks ◽

Bladed Disk

Abstract During fast gas-turbine engine acceleration and deceleration the transient vibration effects in bladed disk vibration become significant and the transient response has to be calculated. In this paper an effective method is developed for efficient calculations of the transient vibration response for mistuned bladed disks under varying rotation speeds. The method uses the large-scale finite element modelling of the bladed disks allowing the accurate description of the dynamic properties of the mistuned bladed disks. The effects of the varying rotation speed on the natural frequencies and mode shapes of a mistuned bladed disk and its effects on the amplitude and the spectral composition of the loading are considered. The dependency of the modal characteristics on the rotation speed are based on the evaluation of these characteristics at reference points followed by the interpolation to obtain values at any rotation speed from the operating range. A new method has been developed for the interpolation of mode shapes while preserving the orthogonality and mass-normalization of the mode shapes. The method of mode shape interpolation is elaborated for tuned and mistuned bladed disks. The accuracy and efficiency of the method is demonstrated on test examples and on analysis of transient forced response of realistic bladed discs.

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