FATIGUE BEHAVIOR OF WELDED BEAMS

The fatigue behavior of welded steel beams is evaluated by using the fracture-mechanics concepts of stable crack growth. A fracture-mechanics model for cracks originating from the pores in the web-to-flange fillet weld is developed. Estimates of the stress-intensity factor are made that numerically describe the initial flaw condition. With the final crack size known, a theoretical crack-growth equation was derived from the fatigue test data of the welded beams. The derived relationship compares well with actual crack-growth measurements on a welded beam and available data from crack-growth specimens. The regime of crack growth, where most of the time is spent growing a fatigue crack in a structural element, is shown to correspond to growth rates below 10 to the minus 6 power in. per cycle. Few experimental crack-growth data are available at this level. It is concluded that the fracture-mechanics concepts can be used to analyze fatigue behavior and to rationally evaluate the major variables that influence the fatigue life of welded beams.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1972/400/400-004.pdf
• Supplemental Notes:
  • Sponsored by Committee on Steel Superstructures. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Hirt, Manfred A
  • Fisher, John W
• Conference:
  • 51st Annual Meeting of the Highway Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1972-1-17 to 1972-1-21
• Publication Date: 1972

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 4-15
• Monograph Title: Bridge design, construction and repair
• Serial:
  • Highway Research Record
  • Issue Number: 400
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Beams; Bridges; Fracture mechanics; Metal bridges; Steel bridges; Welds
• Old TRIS Terms: Welded steel beams
• Subject Areas: Bridges and other structures; Railroads;

Filing Info

• Accession Number: 00043902
• Record Type: Publication
• Report/Paper Numbers: ISBN 0-309-02072-7
• Files: TRIS, TRB
• Created Date: Jun 1 1976 12:00AM