Identification of mistuning characteristics of bladed disks from free response data

Marc Mignolet, Alejandro Rivas-Guerra

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

The focus of the present investigation is on the estimation of the dynamic properties, i.e. masses, stiffnesses, natural frequencies, mode shapes and their statistical distributions, of turbomachine blades to be used in the accurate prediction of the forced response of mistuned bladed disks. As input to this process, it is assumed that the lowest natural frequencies of the blades alone have been experimentally measured, for example in a broach block test. Since the number of measurements is always less than the number of unknowns, this problem is indeterminate in nature. Two distinct approaches will be investigated to resolve the shortfall of data. The first one relies on the imposition of as many constraints as needed to insure a unique solution to this identification problem. Specifically, the mode shapes and modal masses of the blades are set to their design/tuned counterparts while the modal stiffnesses are varied from blade-to-blade to match the measured natural frequencies. The second approach, based on the maximum likelihood principle, yields estimates of all the structural parameters of the blades through the minimization of a specified `cost function'. The accuracy of these two techniques in predicting the forced response of mistuned bladed disks will be assessed on simple dynamic models of the blades.

Original languageEnglish (US)
Title of host publicationAmerican Society of Mechanical Engineers (Paper)
Editors Anon
PublisherASME
EditionGT
StatePublished - 1998
EventProceedings of the 1998 International Gas Turbine & Aeroengine Congress & Exhibition - Stockholm, Sweden
Duration: Jun 2 1998Jun 5 1998

Other

OtherProceedings of the 1998 International Gas Turbine & Aeroengine Congress & Exhibition
CityStockholm, Sweden
Period6/2/986/5/98

ASJC Scopus subject areas

  • Mechanical Engineering

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