scholarly journals Experimental Mistuning Identification in Bladed Disks Using a Component-Mode-Based Reduced-Order Model

AIAA Journal ◽  
2009 ◽  
Vol 47 (5) ◽  
pp. 1277-1287 ◽  
Author(s):  
John A. Judge ◽  
Christophe Pierre ◽  
Steven L. Ceccio
Keyword(s):  
Reduced Order Model ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order

Mistuning Identification of Bladed Disks Using a Fundamental Mistuning Model—Part II: Application

2004 ◽  
Vol 126 (1) ◽  
pp. 159-165 ◽  
Author(s):  
D. M. Feiner ◽  
J. H. Griffin
Keyword(s):  
Experimental Data ◽  
System Identification ◽  
Prior Knowledge ◽  
Experimental Validation ◽  
Reduced Order Model ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order ◽  
Vibratory Response ◽  
Basic Version

This paper is the second in a two-part study of identifying mistuning in bladed disks. It presents experimental validation of a new method of mistuning identification based on measurements of the vibratory response of the system as a whole. As a system-based method, this approach is particularly suited to integrally bladed rotors, whose blades cannot be removed for individual measurements. The method is based on a recently developed reduced-order model of mistuning called the fundamental mistuning model (FMM) and is applicable to isolated families of modes. Two versions of FMM system identification are applied to the experimental data: a basic version that requires some prior knowledge of the system’s properties, and a somewhat more complex version that determines the mistuning completely from experimental data.

Vibration Control for Integrally Bladed Disks Using Friction Ring Dampers

2007 ◽  
Author(s):  
Denis Laxalde ◽  
Fabrice Thouverez ◽  
Jean-Pierre Lombard
Keyword(s):  
Frequency Domain ◽  
Forced Response ◽  
Reduced Order Model ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order ◽  
Design And Optimization ◽  
Beam Elements ◽  
Parametric Studies ◽  
Frequency Domain Approach

A damping strategy for integrally bladed disks (blisks) is discussed in this paper; this involves the use of friction rings located underside the wheel of bladed disks. The forced response of the blisk with friction rings is derived in the frequency domain using a frequency domain approach known as Dynamic Lagrangian Frequency-Time method. The blisk is modeled using a reduced-order model and the rings are modeled using beam elements. The results of some numerical simulations and parametric studies are presented. The range of application of this damping device is discussed. Parametric studies are presented and allow to understand the dissipation phenomena. Finally some design and optimization guidelines are given.

On Damping Entire Bladed Disks Through Dampers on Only a Few Blades

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Javier Avalos ◽  
Marc P. Mignolet
Keyword(s):  
Optimum Design ◽  
Forced Response ◽  
Reduced Order Model ◽  
Order Model ◽  
Bladed Disks ◽  
Single Degree Of Freedom ◽  
Reduced Order ◽  
Bladed Disk ◽  
Single Degree ◽  
Random Mistuning

The focus of this paper is on demonstrating the potential to damp entire bladed disks using dampers on only a fraction of the blades. This problem is first considered without the presence of random mistuning, and it is demonstrated that a few dampers at optimized locations can lead to a significant reduction in the forced response of the entire bladed disk. Unfortunately, this optimum design may not be robust with respect to random mistuning and a notable fraction of the reduction in forced response obtained may disappear because of mistuning. To regain the reduction in forced response but with mistuning present, robustness to mistuning is enhanced by using intentional mistuning in addition to dampers. The intentional mistuning strategy selected here is the A/B pattern mistuning in which the blades all belong to either type A or B. An optimization effort is then performed to obtain the best combination of A/B pattern and damper location to minimize the mistuned forced response of the disk. The addition of intentional mistuning in the system is shown to be very efficient, and the optimum bladed disk design does indeed exhibit a significant reduction in mistuned forced response as compared with the tuned system. These findings were obtained on both single-degree-of-freedom per blade-disk models and a reduced order model of a blisk.

On Damping Entire Bladed Disks Through Dampers on Only a Few Blades

2008 ◽  
Author(s):  
Javier Avalos ◽  
Marc P. Mignolet
Keyword(s):  
Optimum Design ◽  
Forced Response ◽  
Reduced Order Model ◽  
Order Model ◽  
Bladed Disks ◽  
Single Degree Of Freedom ◽  
Reduced Order ◽  
Bladed Disk ◽  
Single Degree ◽  
Random Mistuning

The focus of this paper is on demonstrating the potential to damp entire bladed disks using dampers on only a fraction of the blades. This problem is first considered without the presence of random mistuning and it is demonstrated that a few dampers at optimized locations can lead to a significant reduction in the forced response of the entire bladed disk. Unfortunately, this optimum design may not be robust with respect to random mistuning and a notable fraction of the reduction in forced response obtained may disappear because of mistuning. To regain the reduction in forced response but with mistuning present, robustness to mistuning is enhanced by using intentional mistuning in addition to dampers. The intentional mistuning strategy selected here is the A/B pattern mistuning in which the blades all belong to either type A or B. An optimization effort is then performed to obtain the best combination of A/B pattern and damper location to minimize the mistuned forced response of the disk. The addition of intentional mistuning in the system is shown to be very efficient and the optimum bladed disk design does indeed exhibit a significant reduction of mistuned forced response as compared to the tuned system. These findings were obtained on both single-degree-of-freedom per blade disk models and a reduced order model of a blisk.

A Reduced Order Model for Nonlinear Dynamics of Mistuned Bladed Disks With Shroud Friction Contacts

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
S. Mehrdad Pourkiaee ◽  
Stefano Zucca
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Analysis ◽  
Forced Response ◽  
Reduced Order Model ◽  
Reduced Model ◽  
Synthesis Methods ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order ◽  
Bladed Disk

A new reduced order modeling technique for nonlinear vibration analysis of mistuned bladed disks with shrouds is presented. The developed reduction technique employs two component mode synthesis methods, namely, the Craig-Bampton (CB) method followed by a modal synthesis based on loaded interface (LI) modeshapes (Benfield and Hruda). In the new formulation, the fundamental sector is divided into blade and disk components. The CB method is applied to the blade, where nodes lying on shroud contact surfaces and blade–disk interfaces are retained as master nodes, while modal reductions are performed on the disk sector with LIs. The use of LI component modes allows removing the blade–disk interface nodes from the set of master nodes retained in the reduced model. The result is a much more reduced order model (ROM) with no need to apply any secondary reduction. In the paper, it is shown that the ROM of the mistuned bladed disk can be obtained with only single-sector calculation, so that the full finite element model of the entire bladed disk is not necessary. Furthermore, with the described approach, it is possible to introduce the blade frequency mistuning directly into the reduced model. The nonlinear forced response is computed using the harmonic balance method and alternating frequency/time domain approach. Numerical simulations revealed the accuracy, efficiency, and reliability of the new developed technique for nonlinear vibration analysis of mistuned bladed disks with shroud friction contacts.

Reduced Order Model for a Two Stage Gas Turbine Including Mistuned Bladed Disks and Shaft Interaction

2009 ◽  
Author(s):  
Luis A. Boulton ◽  
Euro Casanova
Keyword(s):  
Finite Element ◽  
Gas Turbine ◽  
Reduced Order Model ◽  
Mode Shapes ◽  
Order Model ◽  
Two Stage ◽  
Bladed Disks ◽  
Reduced Order ◽  
Bladed Disk ◽  
The Impact

A number of previous works have suggested that in some cases the interaction between shaft and bladed disk modes could significantly modify the dynamics of the whole assembly i.e. the bladed disks mounted on a flexible shaft. This paper presents the application of a previously published reduced-order modeling technique to the dynamical modeling of a real two stage gas turbine, including the bladed disks and the shaft. In the resulting reduce order model, mistuning is included in the bladed disk models and the shaft is modeled using beam finite elements according to the classical rotordynamic approach. Generation of finite element parent model for the real turbine is presented and discussed as well as simplifications used in order to generate the reduced order model. Comparisons are made between the reduced model and the full finite element solution for free response frequencies and mode shapes in order to assess the methodology and to evaluate the impact of simplifying hypothesis considered in model generation. Finally, this work also shows interaction between shaft modes and bladed disk modes, therefore confirming that stage independent analysis might not be adequate for predicting the global dynamic response of some turbomachinery rotors.

Mistuning Identification of Bladed Disks Using a Fundamental Mistuning Model—Part I: Theory

2004 ◽  
Vol 126 (1) ◽  
pp. 150-158 ◽  
Author(s):  
D. M. Feiner ◽  
J. H. Griffin
Keyword(s):  
Experimental Data ◽  
System Identification ◽  
Prior Knowledge ◽  
Reduced Order Model ◽  
New Method ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order ◽  
Vibratory Response ◽  
Basic Version

This paper is the first in a two-part study of identifying mistuning in bladed disks. It develops a new method of mistuning identification based on measurements of the vibratory response of the system as a whole. As a system-based method, this approach is particularly suited to integrally bladed rotors, whose blades cannot be removed for individual measurements. The method is based on a recently developed reduced order model of mistuning called the fundamental mistuning model (FMM) and is applicable to isolated families of modes. Two versions of FMM system identification are presented: a basic version that requires some prior knowledge of the system’s properties, and a somewhat more complex version that determines the mistuning completely from experimental data.

A Reduced Order Model for Nonlinear Dynamics of Mistuned Bladed Disks With Shroud Friction Contacts

2018 ◽  
Author(s):  
S. Mehrdad Pourkiaee ◽  
Stefano Zucca
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Analysis ◽  
Forced Response ◽  
Reduced Order Model ◽  
Reduced Model ◽  
Order Model ◽  
Bladed Disks ◽  
Statistical Characterization ◽  
Reduced Order ◽  
Bladed Disk

A new reduced order modeling technique for nonlinear vibration analysis of mistuned bladed disks with shrouds is presented. It has been shown in the literature that the loss of cyclic symmetry properties which is known as mistuning could considerably increase the response level, localize the vibration around few number of blades and finally bring high cyclic fatigue. The developed reduction technique employs two component mode synthesis methods, namely, the Craig-Bampton (CB) method followed by a modal synthesis based on loaded interface modeshapes (Benfield and Hruda). In the new formulation the fundamental sector is divided into blade and disk components. The CB method is applied to the blade, where nodes lying on shroud contact surfaces and blade-disk interfaces are retained as master nodes, while modal reductions is performed on the disk sector with loaded interfaces. The use of loaded interface component modes allows removing the blade-disk interface nodes from the set of master nodes retained in the reduced model. The result is a much more reduced order model with no need to apply any secondary reduction. In the paper it is shown that the reduced order model of the mistuned bladed disk can be obtained with only single-sector calculation, so that the full finite element model of the entire bladed disk is not necessary. Furthermore, with the described approach it is possible to introduce the blade frequency mistuning directly into the reduced model. In this way, reduction is performed only once in case of multiple analyses, necessary for statistical characterization of the nonlinear response of the system. The nonlinear forced response is computed using the harmonic balance method (HBM) and alternating frequency/time domain (AFT) approach. Friction contacts are introduced into the FE model using a 3D contact element. Numerical simulations revealed the accuracy, efficiency and reliability of the new developed technique for nonlinear vibration analysis of mistuned bladed disks with shroud friction contacts.

Mistuning Identification of Bladed Disks Using a Fundamental Mistuning Model: Part 1 — Theory

2003 ◽  
Author(s):  
D. M. Feiner ◽  
J. H. Griffin
Keyword(s):  
Experimental Data ◽  
System Identification ◽  
Prior Knowledge ◽  
Reduced Order Model ◽  
New Method ◽  
Order Model ◽  
Bladed Disks ◽  
Reduced Order ◽  
Vibratory Response ◽  
Basic Version

This paper is the first in a two-part study of identifying mistuning in bladed disks. It develops a new method of mistuning identification based on measurements of the vibratory response of the system as a whole. As a system-based method, this approach is particularly suited to integrally bladed rotors, whose blades cannot be removed for individual measurements. The method is based on a recently developed reduced order model of mistuning called the Fundamental Mistuning Model, FMM, and is applicable to isolated families of modes. Two versions of FMM system identification are presented: a basic version that requires some prior knowledge of the system’s properties, and a somewhat more complex version that determines the mistuning completely from experimental data.

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