Shaft crack monitoring via torsional vibration analysis; Part 2 - Field applications

Phillip W. Garrett, Edward J. Guindon, Martin W. Trethewey, Mitchell S. Lebold, Kenneth P. Maynard

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

1 Scopus citations


Torsional vibration analysis has shown the potential to provide health diagnostics for rotating equipment. Previously, controlled laboratory experiments have demonstrated the ability to detect and track small changes in the health of a shaft with a progressively grown fatigue crack. The work presented in this paper discusses the practical issues and challenges of moving this technology to field applications. Four general categories are discussed; 1) torsional finite element modeling; 2) field instrumentation; 3) torsional signature analysis, and; 4) lessons learned. The use of a torsional FEM to identify suitable encoder placement in relation to the crack location and the expected changes in the modal frequencies due to crack propagation are discussed. Field implementation issues examined include encoder options, transducers and mounting considerations. Signature analysis topics are order content removal and separation of lateral shaft vibration from the torsion. The lessons learned sections describes the interpretation of test results from several applications including variation in torsional modal frequencies due to normal operation and the difficulty of judging the root cause of an observed frequency shift. The paper concludes with an assessment of the use of torsional vibration for rotating equipment health monitoring.

Original languageEnglish (US)
Title of host publicationIMAC-XXIII
Subtitle of host publicationConference and Exposition on Structural Dynamics - Structural Health Monitoring
StatePublished - 2005
Event23rd Conference and Exposition on Structural Dynamics 2005, IMAC-XXIII - Orlando, FL, United States
Duration: Jan 31 2005Feb 3 2005

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652


Other23rd Conference and Exposition on Structural Dynamics 2005, IMAC-XXIII
Country/TerritoryUnited States
CityOrlando, FL

All Science Journal Classification (ASJC) codes

  • General Engineering
  • Computational Mechanics
  • Mechanical Engineering


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