NONDESTRUCTIVE METHODS OF FATIGUE CRACK DETECTION IN STEEL BRIDGE MEMBERS
This summary of the state-of-the-art in nondestructive inspection methods, evaluates their reliability and adaptability for the detection of fatigue cracks in welded highway bridges. Emphasis is placed on in-situ testing and on the capability of techniques to define cracks accurately in terms of length and depth. The underlying concept of fatigue failure prevention in explained, and five testing techniques are described. Details of X-ray examination are briefly outlined. The X-ray image on film provides a permanent record of the size and shape of the defect in two dimensions; it does not show its position in depth in the part. In ultrasonic examination, instrumentation includes a sound wave generator and pick-up device and a display screen on which the initial and reflected pulse is displayed. The display instrumentation permits estimation of the position, nautre and size of the defect. The details (modifications, advantages and disadvantages) of the dye penetrant examination, the magnetic particle examination and the eddy current examination are discussed. The general features of these five methods are summarized in a chart. The study indicates that the best methods for surface crack detection are magnetic particle and dye penetrant examination. The opinion is also expressed that the ultrasonic examination would be the most effective for fatigue crack detection if only one nondestructive examination system could be used. The current capabilities of nondestructive examination methods are reviewed, and practical field crack detection is discussed.
- Digital Copy:
- An NCHRP staff digest of the essential findings from an interim report on NCHRP Project 12-15, "Detection and Repair of Fatigue Cracking in Highway Bridges," by Alan W. Pense, Lehigh University, Bethlehem, Pennsylvania.
Washington, DC United States 20001
- Publication Date: 1975-1
- Features: References;
- Pagination: 14 p.
- NCHRP Research Results Digest
- Issue Number: 66
- Publisher: Transportation Research Board
- TRT Terms: Beams; Bridge members; Dyes; Eddy currents; Failure; Field tests; Fracture mechanics; Highway bridges; Inspection; Magnetic materials; Metal bridges; Nondestructive tests; Penetrants; State of the art studies; Steel bridges; Testing; Ultrasonic tests; Welds; X ray analysis
- Uncontrolled Terms: Magnetic particle testing
- Old TRIS Terms: Dye penetrant testing; Insitu methods; Welded steel beams; X ray inspection
- Subject Areas: Bridges and other structures; Geotechnology; Highways; Materials;
- Accession Number: 00081856
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Mar 26 1975 12:00AM