Detecting Gear Tooth Fatigue Cracks in Advance of Complete Fracture.

Abstract

Results of using vibration based methods to detect gear tooth fatigue cracks are presented. An experimental test rig was used to fail a number of spur gear specimens through bending fatigue. The gear tooth fatigue crack in each test was initiated through a small notch in the fillet area of a tooth on the gear. The primary purpose of these tests was to verify analytical predictions of fatigue crack propagation direction and rate as a function of gear rim thickness. The vibration signal from a total of three tests was monitored and recorded for gear fault detection research. The damage consisted of complete rim fracture on the two thin rim gears and single tooth fracture on the standard full rim test gear. Vibration-based fault detection methods were applied to the vibration signal both on-line and after the tests were completed. The objectives of this effort were to identify methods capable of detecting the fatigue crack, and determine how far in advance of total failure positive detection was given. Results showed that the fault detection methods failed to respond to the fatigue crack prior to complete rim fracture in the thin rim gear tests. In the standard full rim gear test all of the methods responded to the fatigue crack in advance of tooth fracture; however, only three of the methods responded to the fatigue crack in the early stages of crack propagation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1996
Accession Number
ADA309177

Entities

People

  • David G. Lewicki
  • James J. Zakrajsek

Organizations

  • Glenn Research Center

Tags

DTIC Thesaurus Topics

  • Crack Propagation
  • Cracks
  • Detection
  • Monitoring
  • Physical Properties
  • Reliability
  • Standards
  • Technical Standards
  • Thickness
  • Vibration

Fields of Study

  • Engineering

Readers

  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).