0

Application of Perturbation Methodology and Directional Filtering for Early Rotor Crack Detection FREE

[+] Author Affiliations
Paul Goldman, Agnes Muszynska, Donald E. Bently, Kenwood P. Dayton

BRDRC, Minden, NV

Mauro Garcin

Politecnico di Torino, Torino, Italy

Paper No. 99-GT-225, pp. V004T03A028; 11 pages
doi:10.1115/99-GT-225
From:
  • ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition
  • Volume 4: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; IGTI Scholar Award; General
  • Indianapolis, Indiana, USA, June 7–10, 1999
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-7861-3
  • Copyright © 1999 by ASME

abstract

This paper documents analytical and experimental research of the lateral and torsional responses of a cracked rotor to different types of excitation. The experimental research has been performed on a rotor rig, which emulate a turbogenerator. It includes driving motor coupled to the main rotor, a lateral nonsynchronous perturbation device, and a generator with an electrical field consisting of a constant component (constant torsional load) and a sinusoidal component, provided by a signal generator. The generator was used as a torsional nonsynchronous perturbation device. The midspan of the rotor was modified so that a section could be changed starting with a circular cross-section (undamaged rotor) to the cross-section with transverse crack. The lateral and torsional responses have been measured at two axial locations. The obtained lateral data was processed using directional filtering into forward and reverse components of the corresponding filtered elliptical orbits. The forward component of the lateral response to nonsynchronous perturbation allows to identify overall stiffness reduction and rotating stiffness asymmetry introduced by the change in midspan rotor cross-section, while the reverse component largly depends on the support asymmetry. The nonsynchronous torsional excitation allows identify of the system torsional dynamic stiffness and it’s reduction due to the crack. The ratio of the filtered to 1× or to the perturbation frequency rotor responses at two axial locations was considered as an indicator of a lateral mode shape change due to the crack. The experimental results are compared with the analytical model of the rotor response, which was obtained by the application of a perturbation method of small parameter to the system of nonlinear equations. The equations describe the rotor system with four lateral (two displacements and two inclination angles) and two torsional degrees of freedom.

Copyright © 1999 by ASME
This article is only available in the PDF format.

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In