THE PRINCIPLE OF CONTACTLESS ULTRASONIC FLAW DETECTION OF RAILS

PRINTSIP BESKONTAKNOI UL'TRAZVUKOVOI DEFEKTOSKOPII REL'SOV

The fundamental deficiency of ultrasonic flaw detection is the necessity of ensuring acoustic contact between the probe and the checked object. In this regard the contractless method of flaw detection is very promising; the ultrasonic oscillations are excited in the checked object by means of electromagnetic-acoustic (EMA) converters. Utilized in the capacity of the converter is a flat coil in the form of a spiral or a special form, onto which is fed a high frequency current impulse. The principle of excitation of the contactless ultrasonic oscillations in the rail metal is effected as the EMA converter operates in simultaneous regimen, and its feeding is realized from the impulse generator pulsations. The coefficient of the converter with contactless means of exciting the ultrasonic oscillations is much smaller than with the piezoelectric converters. Therefore, this means cannot be utilized for flaw detection by the echo method. During operation of the reflecting shadow method, it is possible to obtain several ground reflections, which show promise for contactless means for rail flaw detection.

  • Supplemental Notes:
    • Full translation available for reference purposes at the Office of R&D, FRA. Contact Technology Planning Officer.
  • Corporate Authors:

    Ministerstvo Putei Soobshcheniya SSSR

    Novoryazanskaya ul., Dom 12
    Moscow 288,   USSR 
  • Authors:
    • Boldyrev, Iu P
  • Publication Date: 1974

Language

  • Russian

Media Info

  • Features: Figures;
  • Pagination: p. 5-9
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00130273
  • Record Type: Publication
  • Source Agency: Federal Railroad Administration
  • Files: TRIS, USDOT
  • Created Date: Dec 1 1977 12:00AM