TY - GEN
T1 - Direct prediction of the effects of mistuning on the forced response of bladed disks
AU - Mignolet, Marc
AU - Hu, Wei
N1 - Publisher Copyright:
© Copyright 1997 by ASME.
PY - 1997
Y1 - 1997
N2 - In this paper, a novel approach to determine reliable estimates of the moments of the steady state resonant response of a randomly mistimed bladed disk is presented and the use of these moments to accurately predict the corresponding distribution of the amplitude of blade vibration is described. The estimation of the moments of the response is accomplished first by relying on a "joint cumulant closure" strategy that expresses higher order moments in terms of lower order ones. A simple modeling of the error terms of these approximations is also suggested that allows the determination of an improved, or accelerated, estimate of the required moments. The evaluation of the distribution of the amplitude of blade response is then accomplished by matching the moments computed by the cumulant closure with those derived from a three-parameter model recently derived. A first order approximation of the moments obtained for a simple structural model of a bladed disk yields a new parameter that can be used as a measure of the localization of the forced response. Then, numerical results demonstrate that the method provides extremely accurate estimates of the moments for all levels of structural coupling which in turn lead to a description of the amplitude of blade response that closely matches simulation results. Finally, a comparison with existing perturbation techniques clearly shows the increased ucuracy obtained with the proposed joint cumulant closure formulation.
AB - In this paper, a novel approach to determine reliable estimates of the moments of the steady state resonant response of a randomly mistimed bladed disk is presented and the use of these moments to accurately predict the corresponding distribution of the amplitude of blade vibration is described. The estimation of the moments of the response is accomplished first by relying on a "joint cumulant closure" strategy that expresses higher order moments in terms of lower order ones. A simple modeling of the error terms of these approximations is also suggested that allows the determination of an improved, or accelerated, estimate of the required moments. The evaluation of the distribution of the amplitude of blade response is then accomplished by matching the moments computed by the cumulant closure with those derived from a three-parameter model recently derived. A first order approximation of the moments obtained for a simple structural model of a bladed disk yields a new parameter that can be used as a measure of the localization of the forced response. Then, numerical results demonstrate that the method provides extremely accurate estimates of the moments for all levels of structural coupling which in turn lead to a description of the amplitude of blade response that closely matches simulation results. Finally, a comparison with existing perturbation techniques clearly shows the increased ucuracy obtained with the proposed joint cumulant closure formulation.
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U2 - 10.1115/97-GT-404
DO - 10.1115/97-GT-404
M3 - Conference contribution
AN - SCOPUS:84973623308
T3 - Proceedings of the ASME Turbo Expo
BT - Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; IGTI Scholar Award
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1997
Y2 - 2 June 1997 through 5 June 1997
ER -