EFFECT OF WELDMENTS ON THE FATIGUE STRENGTH OF STEEL BEAMS

A PROJECT WAS UNDERTAKEN TO DEVELOP MATHEMATICAL DESIGN RELATIONSHIPS THAT WOULD DEFINE IN GENERAL TERMS THE FATIGUE STRENGTH OF ROLLED AND WELDED BEAMS, ROLLED AND WELDED BEAMS WITH COVER PLATES, AND WELDED BEAMS WITH FLANGE SPLICES UNDER CYCLIC LOADING. IN ALL, 374 STEEL BEAMS WERE MADE AND TESTED, OF WHICH 204 HAD COVER PLATES WITH TWO WELD DETAILS. THE DESIGN VARIABLES WERE GROUPED IN THREE MAJOR CATEGORIES: TYPE OF DETAIL, STRESS CONDITION, AND TYPE OF STEEL. PARTICULAR EMPHASIS WAS LAID ON DETAIL TYPE. MINIMUM, MAXIMUM, AND RANGE WERE THE STRESS CONDITIONS. STEELS A36, A441, AND A514 WERE USED. STRESS RANGE WAS OBSERVED TO ACCOUNT FOR NEARLY ALL THE VARIATION IN CYCLE LIFE OF THE TEST BEAMS AND DETAILS EXAMINED. FOR DESIGN PURPOSES, THE FATIGUE STRENGTH OF A GIVEN WELDED DETAIL PROVED INDEPENDENT OF STEEL STRENGTH. FAILURE TO PROPERLY CONTROL AND MEASURE VARIABLES AFFECTING FATIGUE STRENGTH IS THE MAJOR REASON PREVIOUS STUDIES HAVE PRODUCED CONFLICTING REPORTS ON STRESS VARIABLES AND MATERIAL CHARACTERISTICS. VARIATIONS IN COVER-PLATE GEOMETRY FOR EACH END DETAIL HAD NO SIGNIFICANT EFFECT ON FATIGUE STRENGTH EXCEPT IN BEAMS WITH PLATES WIDER THAN THE BEAM FLANGE AT THE END WITHOUT TRANSVERSE FILLET WELD. TRANSVERSE END WELDS SHOULD BE REQUIRED ON COVER PLATES WIDER THAN THEIR FLANGE, SO AS TO PREVENT A DECREASE IN FATIGUE STRENGTH. PLAIN WELDED BEAMS EXHIBIT LOWER FATIGUE STRENGTH THAN THE BASE METAL. GROOVE-WELDED SPLICES WITH THE REINFORCEMENT REMOVED SHOULD BE DESIGNED FOR FATIGUE USING THE STRESS VALUES FOR WELDED BEAMS. THE RESULTS OF THE STUDIES ON PLAIN ROLLED BEAMS DID NOT CORRELATE WITH EXISTING STUDIES ON PLATE SPECIMENS.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_102.pdf
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00775614
• Supplemental Notes:
  • 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. 114 PP, FIGS, TABS, PHOTS, 63 REF, 11 APP
• Publication Date: 1970

Media Info

• Media Type: Digital/other
• Serial:
  • NCHRP Report
  • Issue Number: 102
  • Publisher: Transportation Research Board
  • ISSN: 0077-5614

Subject/Index Terms

• TRT Terms: Beams; Bridge construction; Bridge foundations; Bridges; Construction; Fatigue strength; Fatigue tests; Girders; Metal bridges; Specifications; Steel; Steel bridges; Steel structures; Structural plates; Weldments; Welds
• Uncontrolled Terms: Steel beams
• Old TRIS Terms: Cover plates; Welded steel beams
• Subject Areas: Bridges and other structures; Construction; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00217044
• Record Type: Publication
• Files: TRIS, ATRI
• Created Date: Feb 8 1971 12:00AM