Technical Reports

Feasibility of Flaw Detection in Railroad Wheels Using Acoustic Signatures

  • 01
  • Oct
  • 1976
AUTHOR: Nagy K.; Finch, R. D.
OFFICE: RPD
REPORT NUMBER: DOT-TSC-FRA-76-6; FRA/ORD-76/290
SUBJECT: Railroad System Oversight
KEYWORDS: Railroad cars, Vehicle wheels, Nondestructive tests, Defects, Acoustic signatures, Cracks, Pattern recognition, Computer printouts, BASIC programming language, ANSYS computer program
ABSTRACT: The feasibility study on the use of acoustic signatures for detection of flaws in railway wheels was conducted with the ultimate objective of development of an intrack device for moving cars. Determinations of the natural modes of vibrating wheels under various conditions are reported. Differences in acoustic signatures are found between good and cracked wheels, including spectral changes and variations in the time decay of sound. Various sounds occurring in normal railroad practice, such as rolling noise on welded rail and over joints and retarder screech were investigated. It was concluded that special purpose impacters will have to be used for a servicable device. Pattern recognition techniques were used for selecting good and bad wheels with a computerized processing scheme. A laboratory demonstration system has been constructed and found to be 85% reliable when system malfunctions are discounted.

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