STUDY ON UNIFIED FATIGUE STRENGTH ESTIMATION METHOD FOR FILLET WELDED PLATE STRUCTURES - 1ST REPORT; SIMPLIFIED CALCULATION METHOD OF HOT SPOT STRESS

There is a hot spot stress (HSS) method where a unified S-N curve is used instead of may curves corresponding to joint category for the estimation of fatigue strength of welded structures. In this paper, the hot spot stress method, which is more reasonable and simpler is discussed for welded plate structures, ship hull structures, the bogie frame of rolling stock, etc. First, stress analysis of simple fillet welded models were carried out, by means of the boundary element method to investigate a simpler calculating method of HSS. As a results, it was found that stress concentration due to weld bead is almost reduced to zero at the point about 30% thickness of the main plate off the weld toe, so long as the plate thickness (t) is within the range used for welded plate structures (3mm less than or equal t less than or equal 18mm). The authors propose a simplified HSS calculation method by defining HSS as a stress at 0.3t from the weld toe (0.3t method) for, mainly ship hull structures. In order to verify the validity of this HSS (0.3t method), fatigue tests were carried out for two types of filled welded joints, i.e., cruciform-tension-type and T-bending-type fillet welded joints. Each type has global stress concentration or no global stress concentration due to the structural discontinuity. Each type has the same local stress concentration due to the weld bead shape. As a results, all S-N data based on hot spot stress range by the 0.3t method gathered within a narrow band independent of structural stress concentration factors. It was confirmed the 0.3t method is applicable for unified fatigue strength estimation of fillet welded plate structures.

  • Supplemental Notes:
    • J Kansai Soc Naval Arch, n 220, Sept 1993, p 159 [8 p, 21 ref, 6 tab, 18 fig]
  • Authors:
    • NIHEI, K
    • Inamura, F
    • Koe, S
  • Publication Date: 1993

Language

  • Japanese

Subject/Index Terms

Filing Info

  • Accession Number: 00716271
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Feb 28 1996 12:00AM