Prediction of mistuning effect of bladed disks using eigensensitivity analysis

Vibration modes with repeated eigenvalues often occur in engineering design and analysis practices due to geometrical symmetries of structural systems such as the cyclic symmetry of bladed disk assemblies of turbomachinery. However, the degeneration of eigenvector space and the resulting discontinui...

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Main Authors: Lin, Rongming, Ng, Teng Yong
Other Authors: School of Mechanical and Aerospace Engineering
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/154626
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1546262021-12-29T08:03:53Z Prediction of mistuning effect of bladed disks using eigensensitivity analysis Lin, Rongming Ng, Teng Yong School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Repeated Eigenvalues Eigensensitivity Analysis Vibration modes with repeated eigenvalues often occur in engineering design and analysis practices due to geometrical symmetries of structural systems such as the cyclic symmetry of bladed disk assemblies of turbomachinery. However, the degeneration of eigenvector space and the resulting discontinuities have prevented useful applications of eigensensitivities to vibration analysis of a wide class of problems with repeated modes. To overcome such difficulties, a new concept of a global design variable is developed in which all intended multivariate design modifications are grouped into a single global design variable. Eigensensitivities have then been formulated for repeated eigenvalues from which accurate predictions of vibration characteristics can be made. Further, second order eigenvalue derivatives are also employed to further improve the accuracy of predicted vibration properties. Such newly formulated eigensensitivity analysis has been effectively applied for the first time to the prediction of mistuning effect of bladed disk assemblies. Numerical results from a realistic discrete parameter model of a bladed disk have demonstrated that not only natural frequencies and mode shapes can be predicted very accurately, but also blade vibration responses under engine order excitations. In addition, the proposed eigensensitivty analysis can predict the statistical variations of blade vibrations under random mistuning. Finite element modeling and vibration testing of a practical bladed disk structure have been carried out to demonstrate the practical potential of the proposed method to be possibly integrated into finite element analysis for structural modification predictions, especially for structures with repeated eigenvalues such as bladed disks. 2021-12-29T08:03:53Z 2021-12-29T08:03:53Z 2020 Journal Article Lin, R. & Ng, T. Y. (2020). Prediction of mistuning effect of bladed disks using eigensensitivity analysis. Engineering Structures, 212, 110416-. https://dx.doi.org/10.1016/j.engstruct.2020.110416 0141-0296 https://hdl.handle.net/10356/154626 10.1016/j.engstruct.2020.110416 2-s2.0-85081611682 212 110416 en Engineering Structures © 2020 Elsevier Ltd. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Mechanical engineering
Repeated Eigenvalues
Eigensensitivity Analysis
spellingShingle Engineering::Mechanical engineering
Repeated Eigenvalues
Eigensensitivity Analysis
Lin, Rongming
Ng, Teng Yong
Prediction of mistuning effect of bladed disks using eigensensitivity analysis
description Vibration modes with repeated eigenvalues often occur in engineering design and analysis practices due to geometrical symmetries of structural systems such as the cyclic symmetry of bladed disk assemblies of turbomachinery. However, the degeneration of eigenvector space and the resulting discontinuities have prevented useful applications of eigensensitivities to vibration analysis of a wide class of problems with repeated modes. To overcome such difficulties, a new concept of a global design variable is developed in which all intended multivariate design modifications are grouped into a single global design variable. Eigensensitivities have then been formulated for repeated eigenvalues from which accurate predictions of vibration characteristics can be made. Further, second order eigenvalue derivatives are also employed to further improve the accuracy of predicted vibration properties. Such newly formulated eigensensitivity analysis has been effectively applied for the first time to the prediction of mistuning effect of bladed disk assemblies. Numerical results from a realistic discrete parameter model of a bladed disk have demonstrated that not only natural frequencies and mode shapes can be predicted very accurately, but also blade vibration responses under engine order excitations. In addition, the proposed eigensensitivty analysis can predict the statistical variations of blade vibrations under random mistuning. Finite element modeling and vibration testing of a practical bladed disk structure have been carried out to demonstrate the practical potential of the proposed method to be possibly integrated into finite element analysis for structural modification predictions, especially for structures with repeated eigenvalues such as bladed disks.
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Lin, Rongming
Ng, Teng Yong
format Article
author Lin, Rongming
Ng, Teng Yong
author_sort Lin, Rongming
title Prediction of mistuning effect of bladed disks using eigensensitivity analysis
title_short Prediction of mistuning effect of bladed disks using eigensensitivity analysis
title_full Prediction of mistuning effect of bladed disks using eigensensitivity analysis
title_fullStr Prediction of mistuning effect of bladed disks using eigensensitivity analysis
title_full_unstemmed Prediction of mistuning effect of bladed disks using eigensensitivity analysis
title_sort prediction of mistuning effect of bladed disks using eigensensitivity analysis
publishDate 2021
url https://hdl.handle.net/10356/154626
_version_ 1722355284454670336