Mistuning parameter identification and vibration localization analysis of the integration rotor

2021 ◽  
pp. 095441002098146
Author(s):  
Hongyun Sun ◽  
Huiqun Yuan
Keyword(s):  
Synthesis Method ◽  
Coupling Factor ◽  
Coupling Vibration ◽  
Mode Localization ◽  
Reduced Order ◽  
Vibration Localization ◽  
Localization Phenomenon ◽  
Localization Analysis ◽  
Mode Truncation ◽  
Hybrid Interface

This paper deals with the coupling vibration characteristic of the disk-blade-shaft integration rotor. First, a reduced-order model (ROM) based on an improved hybrid interface component mode synthesis method (IHISCMSM) is carried out, which takes the prestress effect into account. The frequency of the disk-blade-shaft integration rotor at different rotating speeds are calculated and the influence of selecting different mode truncation numbers is investigated. In order to quantitatively evaluate the coupling degree of blade and disk, the coupling factor is defined from the perspective of strain energy, and the influence of prestress on system’s dynamic is discussed. Then, an experimental modal analysis is performed on blades to identify the mistuning parameters, and the mode localization of the disk-blade-shaft integration rotor is analyzed with and without blade mistuning. The results indicate that there are several types of coupling modes among blade, disk and shaft of the integration rotor. After considering the prestress, the frequency increases, and the axial coupling vibration degree and radial coupling vibration degree of the integration rotor change. The mode localization of mistuned rotor is more likely to occur in the modes dominated by mistuning stage blades. There also exists a subtle mode localization phenomenon for tuned integration rotor.

Vibration reduction optimization of the mistuned bladed disk considering the prestress

2017 ◽  
Vol 233 (1) ◽  
pp. 226-239 ◽  
Author(s):  
Hongyuan Zhang ◽  
Huiqun Yuan ◽  
Wenjun Yang ◽  
Tianyu Zhao
Keyword(s):  
Finite Element ◽  
Optimization Algorithm ◽  
Synthesis Method ◽  
Reduced Order Model ◽  
Component Mode Synthesis ◽  
Order Model ◽  
Blade Vibration ◽  
Reduced Order ◽  
Vibration Localization ◽  
Bladed Disk

Ignoring the effect of prestress can increase the gap between the actual results and research results, which is not conducive to improve the vibration localization of bladed disk system and the finite element calculation. To improve the vibration localization and computational efficiency, the prestressed component mode synthesis method (PCMSM) was adopted to establish the finite element reduced-order model considering prepress. Since the main calculation precision of the prestressed component mode synthesis method was the mode truncation number, calculation was made to the eigenfrequency of different mode truncations; the contrast and analysis were made to the calculation result of blisk model, minimum mode truncation number under the above calculation precision was obtained, and freedom of the model was greatly reduced. The finite element reduced-order model was collocated to make an analysis of the vibration response characteristics of mistuned bladed disk. From the aforementioned analysis, the maximum amplitude of mistuned bladed disk was not only associated with the mistuning value of blade but also related to the frequency of adjacent blade; on the basis of such a rule, the finite element reduced-order model was adopted to raise an optimization algorithm for the blade vibration reduction and arrangement. Results have revealed that the optimization algorithm has made an adequate consideration of both model precision and calculation speed. The maximum dimensionless amplitude of blade vibration under three mistuning patterns and upon optimization is greatly reduced by 32.8%, 30.1%, and 28%. The localization factor of blade vibration under three mistuning patterns and upon optimization is greatly reduced by 64%, 68.5%, and 57.2%. The optimization algorithm based on the prestressed component mode synthesis method gets the optimization value by not more than 15 iterations. The optimization algorithm has greatly reduced the amplitude of the blade and obviously dampened vibration localization of the bladed disk system.

Vibration Localization in Dual-Span, Axially Moving Beams: Formulation and Results

1993 ◽  
Author(s):  
A. A. N. Al-jawi ◽  
Christophe Pierre ◽  
A. G. Ulsoy
Keyword(s):  
Axially Moving Beam ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Modes ◽  
Axial Tension ◽  
Localization Phenomenon ◽  
Moving Beam ◽  
Solution Methods ◽  
Axially Moving Beams ◽  
Axially Moving

Abstract An investigation of the vibration localization phenomenon in dual-span, axially moving beams is presented. The effects of a tension difference among the spans, also referred to as disorder, on the natural modes of free vibration are studied in terms of interspan coupling and transport speed. The equations governing the transverse vibration of the two-span, axially moving beam are derived through Hamilton’s principle and solution methods are developed. Results demonstrate that normal mode localization indeed occurs for both stationary and translating disordered two-span beams, especially for small interspan coupling. The occurrence of localization is characterized by a peak deflection much greater in one span than in the other. In the stationary disordered case, localization becomes more pronounced as interspan coupling decreases, i.e., as the span axial tension increases. In the axially moving disordered case, the transport speed has a significant influence on localization, and generally speaking localization becomes stronger with increasing speed. For a moving beam with identical spans, the two loci of each pair of natural frequencies may exhibit one or more crossing(s) (depending on the value of tension) when plotted against the axial transport speed. These crossings become veerings when the beam is disordered, and localization is strongest at those speeds where the eigenvalue veerings occur.

Nonlinear Vibrations of Two-Span Composite Laminated Plates with Equal and Unequal Subspan Lengths

2017 ◽  
Vol 9 (6) ◽  
pp. 1485-1505
Author(s):  
Lingchang Meng ◽  
Fengming Li
Keyword(s):  
Multiple Scales ◽  
Equations Of Motion ◽  
Primary Resonance ◽  
Laminated Plates ◽  
Laminated Plate ◽  
Composite Laminated Plate ◽  
Vibration Localization ◽  
Composite Laminated Plates ◽  
Localization Phenomenon ◽  
Harmonic Resonance

AbstractThe nonlinear transverse vibrations of ordered and disordered two-dimensional (2D) two-span composite laminated plates are studied. Based on the von Karman's large deformation theory, the equations of motion of each-span composite laminated plate are formulated using Hamilton's principle, and the partial differential equations are discretized into nonlinear ordinary ones through the Galerkin's method. The primary resonance and 1/3 sub-harmonic resonance are investigated by using the method of multiple scales. The amplitude-frequency relations of the steady-state responses and their stability analyses in each kind of resonance are carried out. The effects of the disorder ratio and ply angle on the two different resonances are analyzed. From the numerical results, it can be concluded that disorder in the length of the two-span 2D composite laminated plate will cause the nonlinear vibration localization phenomenon, and with the increase of the disorder ratio, the vibration localization phenomenon will become more obvious. Moreover, the amplitude-frequency curves for both primary resonance and 1/3 sub-harmonic resonance obtained by the present analytical method are compared with those by the numerical integration, and satisfactory precision can be obtained for engineering applications and the results certify the correctness of the present approximately analytical solutions.

Vibration Localization in Band/Wheel Systems: Theory and Experiment

1993 ◽  
Author(s):  
A. A. N. Al-jawi ◽  
A. G. Ulsoy ◽  
Christophe Pierre
Keyword(s):  
Simple Model ◽  
Coupling Model ◽  
Complex Model ◽  
Translation Speed ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Modes ◽  
Theoretical Predictions ◽  
Axially Moving Beams ◽  
Axially Moving

Abstract An investigation of the localization phenomenon in band/wheel systems is presented. The effects of tension disorder, interspan coupling, and translation speed on the confinement of the natural modes of free vibration are investigated both theoretically and experimentally. Two models of the band/wheel system dynamics are discussed; a simple model proposed by the authors [1] and a more complete model originally proposed by Wang and Mote [9]. The results obtained using the simple interspan coupling model reveal phenomena (i.e., eigenvalue crossings and veerings and associated mode localization) that are qualitatively similar to those featured by the more complex model of interspan coupling, thereby confirming the usefulness of the simple coupling model. The analytical predictions of the two models are validated by an experiment. A very good agreement between the experimental results and the theoretical ones for the simple model is observed. While both the experimental observations and the theoretical predictions show that a beating phenomenon takes place for ordered stationary and axially moving beams, beating is destroyed (indicating the occurrence of localization) when any small tension disorder is introduced especially for small interspan coupling (i.e., when localization is strongest).

Effect of a local crack on the dynamic characteristics of a rotating grouped blade disc

2001 ◽  
Vol 216 (4) ◽  
pp. 447-457 ◽  
Author(s):  
B W Huang ◽  
J H Kuang
Keyword(s):  
Dynamic Characteristics ◽  
Rotational Speed ◽  
Crack Depth ◽  
Numerical Results ◽  
Galerkin’S Method ◽  
Mode Localization ◽  
Torsion Spring ◽  
Crack Distribution ◽  
Localization Phenomenon ◽  
Blade Crack

The effects of a local blade crack and the group arrangement on the mode localization in a rotating turbodisc are studied in this paper. Periodically coupled Euler—Bernoulli beams are used to approximate the grouped and shrouded turboblades. A two-span beam with a torsion spring is used to model the cracked blade. The crack depth characterizes the stiffness of the assumed torsion spring. Galerkin's method is applied to formulate the localization equations of the grouped turbodisc system. Numerical results indicate that the crack depth, crack distribution and rotational speed in a rotating grouped blade disc may significantly affect the localization phenomenon.

scholarly journals Identification and influence factors analysis of blade crack mistuning in hard-coated blisk based on modified component mode mistuning reduced-order model

2020 ◽  
pp. 146134842097138
Author(s):  
Kunpeng Xu ◽  
Xianfei Yan ◽  
Dongxu Du ◽  
Wei Sun
Keyword(s):  
Crack Length ◽  
Influence Factors ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Crack Location ◽  
Vibration Localization ◽  
Identification Method ◽  
Bending Modes ◽  
Blade Crack

Blade crack will cause severe mistuning of hard-coated blisks, which will lead to vibration localization. To identify crack mistuning and analyze influence factors, in this study, a mistuning identification method of blade cracks in hard-coated blisks is presented based on modified component mode mistuning reduced-order model, in which the hard-coated blisk with blade crack is decomposed into a substructure of tuned hard-coated blisk and a substructure of coated blade with cracks. Crack mistuning of each coated blade can be obtained by a single identification calculation. After verifying the rationality of this identification method, the influence factors of blade crack mistuning are analyzed. The influence factors include the crack location on the coated blade (cracks occurring only in coating or only in blade substrate or both in blade substrate and coating), crack length, crack position in the radial direction of the blisk, and modal data type of coated blisk used for mistuning identification calculation. The research results show that, with the increase of crack length, the mistuning of crack occurring only in the coating does not increase continuously but decreases firstly and then increases. For the first bending modes, the closer the blade crack is to the blade root, the larger the mistuning is. For the second bending modes, the blade crack located at the position of maximum modal displacement will produce large mistuning. For hard-coated blisk with blade crack, these crack mistuning variation rules are of great significance to the dynamic analysis and the determination of the crack location.

Geometric Mistuning Reduced-Order Model Development Utilizing Bayesian Surrogate Models for Component Mode Calculations

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Joseph A. Beck ◽  
Jeffrey M. Brown ◽  
Alex A. Kaszynski ◽  
Emily B. Carper ◽  
Daniel L. Gillaugh
Keyword(s):  
Periodic Structures ◽  
Model Development ◽  
Element Model ◽  
Forced Response ◽  
Mode Shapes ◽  
Order Model ◽  
Mode Localization ◽  
Reduced Order ◽  
Structural Periodicity ◽  
Computationally Intensive

AbstractIntegrally bladed rotors (IBRs) are meant to be rotationally periodic structures. However, unique variations in geometries and material properties from sector-to-sector, called mistuning, destroy the structural periodicity. This results in mode localization that can induce forced response levels greater than what is predicted with a tuned analysis. Furthermore, mistuning and mode localization are random processes that require stochastic treatments when analyzing the distribution of fleet responses. Generating this distribution can be computationally intensive when using the full finite element model (FEM). To overcome this expense, reduced-order models (ROMs) have been developed to accommodate fast calculations of mistuned forced response levels for a fleet of random IBRs. Usually, ROMs can be classified by two main families: frequency-based and geometry-based methods. Frequency-based ROMs assume mode shapes do not change due to mistuning. However, this assumption has been shown to cause errors that propagate to the fleet distribution. To circumvent these errors, geometry-based ROMs have been developed to provide accurate predictions. However, these methods require recalculating modal data during ROM formulations. This increases the computational expense in computing fleet distributions. A new geometry-based ROM is presented to reduce this cost. The developed ROM utilizes a Bayesian surrogate model in place of sector modal calculations required in ROM formulations. The method, surrogate modal analysis for geometry mistuning assessments (SMAGMA), will propagate uncertainties of the surrogate prediction to forced response. ROM accuracies are compared to the true forced response levels and results computed by a frequency-based ROM.

Dynamic Characteristics of a Mistuned Heat Exchanger in Cross-Flow

2007 ◽  
Author(s):  
Bo-Wun Huang ◽  
Huang-Kuang Kung ◽  
Jao-Hwa Kuang
Keyword(s):  
Heat Exchanger ◽  
Shock Waves ◽  
Dynamic Characteristics ◽  
Tube Bundle ◽  
Cooling Water ◽  
Cross Flow ◽  
Water Film ◽  
Local Defect ◽  
Mode Localization ◽  
Localization Phenomenon

The dynamic behaviors of tubes of a heat exchanger are frequently affected by the existence of local flaw. These tubes are worn from the hot-cold fluid shock waves. This local defect may alter the tube dynamics and introduce mode localization in the periodically arranged tube array. The variation of the dynamic characteristics of a component cooling water heat exchanger with wear tubes in cross-flow is investigated in this study. Periodically coupled cooling tubes are used to approximate a heat exchanger. Each tube is considered to be coupled to adjacent tubes through the squeezed water film in the gaps. This work addresses the probability of mode localization is occurring in a heat exchanger in cross-flow. A dynamic model of the coupled tube bundle is proposed. The numerical results reveal that the local defect in a tube array may introduce the so-called mode localization phenomenon in a periodically coupled tube bundle.

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