RATIONAL APPROACH TO THE ESTABLISHMENTS OF ACCEPTANCE LEVELS OF HEAVY WELDMENTS

Fatigue growth of a surface crack and an embedded crack was analyzed for heavy weldments of high strength steels including HY-80, HY-100, HY-130, HP9-4, and maraging steels. Fatigue life of structures subjected to hoop stresses was obtained by the iteration method of the crack growth under non-uniform welding residual stresses in weldments. Various effects on fatigue life were investigated including acting hoop stresses, profiles of welding residual stresses, fracture toughness of welds and coefficients in the crack growth rate equations. Probabilistic distribution functions of fatigue life were determined based on deviation of physical properties of weldments in order to aid one to make decisions associated with welding fabrication rationally. The expected utility under uncertain fatigue life leads to establish standards of permissible initial weld flaws and the acceptance criteria of repair welding and stress relieving anneal. In an effort to make optimization of material selection for a pressure hull of a deep submersible, two dimensional utility with respect to a buoyancy factor and fatique life was used.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  USA  02139
  • Authors:
    • Yurioka, N
  • Publication Date: 1972-5

Subject/Index Terms

Filing Info

  • Accession Number: 00044164
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Files: TRIS
  • Created Date: May 11 1973 12:00AM