A method for the determination of stress intensity factors of elliptical cracks and the fatigue growth of such cracks due to load cycling is described. In essence, the stress intensity factors are computed based on the strain energy release rate approach. A multilevel superelement formulation of the finite element method is used in the numerical calculations. Further, the growth of the crack due to the load cycling is computed employing Paris' crack growth formula. A superelement formulation of the finite element method for elasto-plastic analysis of three-dimensional solids is described. The flow theory of plasticity, the von Mises yield criterion and the isotropic hardening law are adopted. Further, eight-node isoparametric finite elements are used in the numerical calculations. The solution of the nonlinear equations is performed utilizing a combination of load incrementation and equilibrium iterations. A modified Newton-Raphson iteration scheme by which the incremental stiffness matrix is updated once only for each load increment, is used in the calculations. In addition, acceleration factors are used to speed up the rate of covergence during the iteration process. The use of the technique is demonstrated for the elasto-plastic analyses of a thick plate with two edge-cracks and a plate with a central crack.

  • Corporate Authors:

    Norske Veritas

    Grenseveien 92, Etterstad
    Oslo 6,   Norway 
  • Authors:
    • Aamodt, B
  • Publication Date: 1976-2

Media Info

  • Features: References;
  • Pagination: p. 15-26
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00147513
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Feb 16 2003 12:00AM