Recently in Japan, fatigue cracks have been observed in bridges, cranes and tanks. Generally, there is a possibility of two types of fatigue cracks inherent in thin-walled plate girders. A crack which is initiated at the toe of fillet welds of compressions flange-to-web, is called Type-1 crack. Then, a crack at the toe of fillet welds of vertical stiffener-to-web, is called Type-2 crack. Type-1 and -2 cracks are governing ones in homogeneous and hybrid plate girders, respectively. For the fatigue design of deep thin-walled stiffened plate girders of bridges, the paper presents an extensive study on fatigue strength based on observations at the tests of initiation and propagation of the above-mentioned two fatigue cracks. The outline of girder tests and of coupon-type model tests for Type-2 cracks, and then the outline of girder tests and of plate-type and bar-type model tests for Type-1 cracks, are described and the results are discussed. The mechanism of initiation of Type-1 cracks at the bar-type model tests is discussed from the point of fracture mechanics in connection with unavoidable inherent initial defects due to welding or fabrication. Although the application of the test results to design is discussed, the problem of Type-1 cracks is a matter of structural details subjected to displacement-induced secondary bending stress ranges, and the need of further studies is stated. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 120-128
  • Monograph Title: Bridge Engineering. Volume 1
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00183755
  • Record Type: Publication
  • ISBN: 0309026962
  • Files: TRIS, TRB
  • Created Date: Dec 3 1978 12:00AM