scholarly journals Statistical Analysis of the Forced Response of Mistuned Bladed Disks Using Stochastic Reduced Basis Methods

2002 ◽  
Author(s):  
Mamadou Bah ◽  
Prasanth Nair ◽  
Atul Bhaskar ◽  
Andy Keane
Keyword(s):  
Statistical Analysis ◽  
Forced Response ◽  
Reduced Basis ◽  
Bladed Disks ◽  
Reduced Basis Methods

scholarly journals Forced response statistics of mistuned bladed disks: a stochastic reduced basis approach

2003 ◽  
Vol 263 (2) ◽  
pp. 377-397 ◽  
Author(s):  
M.T. Bah ◽  
P.B. Nair ◽  
A. Bhaskar ◽  
A.J. Keane
Keyword(s):  
Forced Response ◽  
Reduced Basis ◽  
Bladed Disks

Piezoelectric Networks for Vibration Suppression of Mistuned Bladed Disks

2007 ◽  
Vol 129 (5) ◽  
pp. 559-566 ◽  
Author(s):  
Hongbiao Yu ◽  
K. W. Wang
Keyword(s):  
Vibration Suppression ◽  
Periodic Structures ◽  
Electric Circuit ◽  
Forced Response ◽  
Bladed Disks ◽  
Vibration Localization ◽  
Network Concept ◽  
Engine Order ◽  
The Individual ◽  
Local Circuits

Extensive investigations have been conducted to study the vibration localization phenomenon and the excessive forced response that can be caused by mistuning in bladed disks. Most previous researches have focused on analyzing∕predicting localization or attacking the mistuning issue via mechanical tailoring. Few have focused on developing effective vibration control methods for such systems. This study extends the piezoelectric network concept, which has been utilized for mode delocalization in periodic structures, to the control of mistuned bladed disks under engine order excitation. A piezoelectric network is synthesized and optimized to effectively suppress vibration in bladed disks. One of the merits of such an approach is that the optimum design is independent of the number of spatial harmonics, or engine orders. Local circuits are first formulated by connecting inductors and resistors with piezoelectric patches on the individual blades. Although these local circuits can function as conventional damped absorber when properly tuned, they do not perform well for bladed disks under all engine order excitations. To address this issue, capacitors are introduced to couple the individual local circuitries. Through such networking, an absorber system that is independent of the engine order can be achieved. Monte Carlo simulation is performed to investigate the effectiveness of the network for a bladed disk with a range of mistuning level of its mechanical properties. The robustness issue of the network in terms of detuning of the electric circuit parameters is also studied. Finally, negative capacitance is introduced and its effect on the performance and robustness of the network is investigated.

Stochastic Reduced Basis Methods

AIAA Journal ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1653-1664 ◽  
Author(s):  
Prasanth B. Nair ◽  
Andrew J. Keane
Keyword(s):  
Reduced Basis ◽  
Reduced Basis Methods

Comparison of advanced reduced-basis methods for transient structural analysis

AIAA Journal ◽  
1993 ◽  
Vol 31 (9) ◽  
pp. 1712-1719 ◽  
Author(s):  
David M. McGowan ◽  
Susan W. Bostic
Keyword(s):  
Structural Analysis ◽  
Reduced Basis ◽  
Reduced Basis Methods

Intentional Response Reduction by Harmonic Mistuning of Bladed Disks With Aerodynamic Damping

2018 ◽  
Author(s):  
Sebastian Willeke ◽  
Lukas Schwerdt ◽  
Lars Panning-von Scheidt ◽  
Jörg Wallaschek
Keyword(s):  
Wave Train ◽  
Wave Mode ◽  
Forced Response ◽  
Mode Shapes ◽  
Bladed Disks ◽  
Nodal Diameter ◽  
Aerodynamic Damping ◽  
Mode Pair ◽  
Localized Mode ◽  
Amplitude Level

A harmonic mistuning concept for bladed disks is analyzed in order to intentionally reduce the forced response of specific modes below their tuned amplitude level. By splitting a mode pair associated with a specific nodal diameter pattern, the lightly damped traveling wave mode of the nominally tuned blisk is superposed with its counter-rotating complement. Consequently, a standing wave is formed in which the former wave train benefits from an increase in aerodynamic damping. Unlike previous analyses of randomly perturbed configurations, the mode-specific stabilization is intentionally promoted through adjusting the harmonic content of the mistuning pattern. Through a re-orientation of the localized mode shapes in relation to the discrete blades, the response is additionally attenuated by an amount of up to 7.6 %. The achievable level of amplitude reduction is analytically predicted based on the properties of the tuned system. Furthermore, the required degree of mistuning for a sufficient separation of a mode pair is derived.

Blade Root Joint Modelling and Analysis of Effects of Their Geometry Variability on the Nonlinear Forced Response of Tuned and Mistuned Bladed Disks

2020 ◽  
Author(s):  
Adam Koscso ◽  
E. P. Petrov
Keyword(s):  
Harmonic Balance Method ◽  
Forced Response ◽  
High Fidelity ◽  
Contact Interactions ◽  
Bladed Disks ◽  
Element Mesh ◽  
Disk Model ◽  
Bladed Disk ◽  
Nonlinear Contact ◽  
Manufacturing Tolerances

Abstract One of the major sources of the damping of the forced vibration for bladed disk structures is the micro-slip motion at the contact interfaces of blade-disk joints. In this paper, the modeling strategies of nonlinear contact interactions at blade roots are examined using high-fidelity modelling of bladed disk assemblies and the nonlinear contact interactions at blade-disk contact patches. The analysis is performed in the frequency domain using multiharmonic harmonic balance method and analytically formulated node-to-node contact elements modelling frictional and gap nonlinear interactions. The effect of the number, location and distribution of nonlinear contact elements are analyzed using cyclically symmetric bladed disks. The possibility of using the number of the contact elements noticeably smaller than the total number of nodes in the finite element mesh created at the contact interface for the high-fidelity bladed disk model is demonstrated. The parameters for the modeling of the root damping are analysed for tuned and mistuned bladed disks. The geometric shapes of blade roots and corresponding slots in disks cannot be manufactured perfectly and there is inevitable root joint geometry variability within the manufacturing tolerances. Based on these tolerances, the extreme cases of the geometry variation are defined and the assessment of the possible effects of the root geometry variation on the nonlinear forced response are performed based on a set of these extreme cases.

Reduced Basis Methods for Fractional Laplace Equations via Extension

2019 ◽  
Vol 41 (6) ◽  
pp. A3552-A3575 ◽  
Author(s):  
Harbir Antil ◽  
Yanlai Chen ◽  
Akil Narayan
Keyword(s):  
Reduced Basis ◽  
Laplace Equations ◽  
Reduced Basis Methods
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