An Equivalent Reduced Modelling Method and its Application to Shaft—Blade Coupled Torsional Vibration Analysis of a Turbine—Generator Set

Okabe, Atsuyuki; Otawara, Yasuhiko; Kaneko, Ryuji; Matsushita, Osami; Namura, Kiyoshi

doi:10.1243/pime_proc_1991_205_026_02

Cited by 22 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This preliminary result means that the danger of unstable blade bending vibration due to shaft torsional excitation exists when exposing the system to torsional vibration excitation frequencies that are lower than the blade natural frequency. 4. CONCLUSIONS A non-linear dynamic model for blade bending vibration under the effect of shaft torsional flexibility is considered in this paper.…”

Section: Letters To the Editormentioning

confidence: 99%

“…The effect of shaft torsional flexibility on the vibrations of rotating blades has not been considered in the previous studies. Okabe et al [4] highlighted the necessity for modelling both blade bending and shaft torsional deformations in turbo-machinery. Al-Bedoor [5], based on multi-body dynamic approach, developed a coupled model for shaft-torsional and blade-bending vibrations in rotors.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Vibration of a Rotating Blade on a Torsionally Flexible Shaft

Al‐Nassar¹,

Al‐Bedoor²

2003

Journal of Sound and Vibration

View full text Add to dashboard Cite

Section: Letters To the Editormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the Vibration of a Rotating Blade on a Torsionally Flexible Shaft

Al‐Nassar¹,

Al‐Bedoor²

2003

Journal of Sound and Vibration

View full text Add to dashboard Cite

“…Crawley et al [5] presented a simplified analytical model for rotating a flexible blade-rigid disc-flexible cantilevered shaft system. Okabe et al [6] addressed an equivalent modeling technique for a blade-shaft system by dividing the system into a shaft plus additional equivalent mass-spring models of blades. Zhang et al [7] presented a method for dynamic analysis of flexible blade-disc-shaft systems by means of the finite element method and a modal synthesis approach.…”

Section: Introductionmentioning

confidence: 99%

A Reduced-Order Model for the Vibration Analysis of Mistuned Blade–Disc–Shaft Assembly

Wang

Zheng

2019

Applied Sciences

View full text Add to dashboard Cite

An effective reduced-order model is presented in this paper for the vibration analysis of a mistuned blade–disc–shaft assembly considering the flexibility of the shaft and the rotordynamic effects. For the sake of accurate modeling and quantitative analysis, three-dimensional (3D) finite element models were employed in obtaining the governing equations of motion with the Coriolis force, centrifugal stiffening, and spin softening effects taken into account. Then, an efficient model order reduction technique based on the coordinate projection by normal modes of tuned assembly and cyclic symmetry analysis was developed for mistuned blade–disc–shaft assembly. The criterion of whether one matrix could be incorporated in cyclic symmetry analysis is presented. During the modeling, the mistuning in blade and disc was taken into account and dealt with independently. In mistuning projection, the blade and disc parts were both projected onto their tuned counterparts of the sector model, where the boundary conditions were set to be fixed and free, respectively. Finally, an example of a blade–disc–shaft assembly was employed to validate the effectiveness of the presented method in free and forced vibration analysis.

show abstract

“…In the work of [4,5], no special attention was given to the coupling between the shaft torsional and blade bending vibrations. Okabe et al [6] reported a study that emphasized the need for modeling the coupled blade bending and shaft torsional vibrations in turbo-machinery. They developed an equivalent model that coupled shaft-torsional and blade-tangential vibrations.…”

Section: Introductionmentioning

confidence: 99%

Natural Frequncies of Coupled Blade‐Bending and Shaft‐Torsional Vibrations

Al‐Bedoor

2006

Shock and Vibration

View full text Add to dashboard Cite

In this study, the coupled shaft-torsional and blade-bending natural frequencies are investigated using a reduced order mathematical model. The system-coupled model is developed using the Lagrangian approach in conjunction with the assumed modes method to discretize the blade bending deflection. The model accounts for the blade stagger (setting) angle, the system rotating speed and its induced stiffening effect. The coupled equations of motion are linearized based on the small deformation theory for the blade bending and shaft torsional deformation to enable calculation of the system natural frequencies for various combinations of system parameters. The obtained coupled eignvalue system is ready for use as a reference for comparison for larger size finite element simulations and for the use as a fast check on natural frequencies for the coupled blade bending and shaft torsional vibrations in the design and diagnostics processes. Some results on the predicted natural frequencies are graphically presented and discussed pertinent to the coupling controlling factors and their effects. In addition, the predicted coupled natural frequencies are validated using the Finite Element Commercial Package (Pro-Mechanica) where good agreements are found.

show abstract

An Equivalent Reduced Modelling Method and its Application to Shaft—Blade Coupled Torsional Vibration Analysis of a Turbine—Generator Set

Cited by 22 publications

References 4 publications

On the Vibration of a Rotating Blade on a Torsionally Flexible Shaft

On the Vibration of a Rotating Blade on a Torsionally Flexible Shaft

A Reduced-Order Model for the Vibration Analysis of Mistuned Blade–Disc–Shaft Assembly

Natural Frequncies of Coupled Blade‐Bending and Shaft‐Torsional Vibrations

Contact Info

Product

Resources

About