ANALYSIS OF OPEN STEEL BOX SECTIONS WITH BRACING

Braced open thin-walled steel box girders under combined bending and torsion were studied. Two model box girders were tested in the elastic range. Analytically, the top bracing of open box sections was converted to an equivalent plate thus forming an equivalent closed box. Experimental results on braced open boxes and computed stresses for the equivalent closed boxes agreed well. Rotations calculated from deflections without adjustment of support rotations were higher than the values computed for the equivalent closed boxes. Deformation of cross section was neglected in the analysis. The stresses in the bracing members were estimated using stresses in the equivalent top plate as loads on a bracing frame. The estimated stresses also compared well with experimental results. Based on the concept of equivalent closed box, a procedure was recommended for the selection of bracing member sizes.

• Supplemental Notes:
  • Sponsored in part by Federal Highway Administration, Washington, D.C. and Pennsylvania Dept. of Transportation, Harrisburg.
• Corporate Authors:

  Lehigh University

  Fritz Engineering Laboratory
  Bethlehem, PA  United States  18015

  Pennsylvania Department of Transportation

  Commonwealth and Forster Streets
  Harrisburg, PA  United States  17120

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • McDonald, R E
  • Chen, Y S
  • Yilmaz, C
  • Yen, B T
• Publication Date: 1973-10

Media Info

• Pagination: 45 p.

Subject/Index Terms

• TRT Terms: Box beams; Box girders; Bracing; Bridge design; Bridges; Deflection; Deformation; Elastic analysis; Girder bridges; Girders; Metal bridges; Shear stress; Steel bridges; Stresses; Structural design
• Old TRIS Terms: Normal stress
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00143209
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: FEL-380.7 Intrm Rpt., FHWA-RD-76-S0504
• Files: NTIS, TRIS, USDOT, STATEDOT
• Created Date: Oct 26 1976 12:00AM