Crack path and life prediction under mixed mode cyclic variable amplitude loading through XFEM


Dirik H., YALÇINKAYA T.

International Journal of Fatigue, vol.114, pp.34-50, 2018 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 114
  • Publication Date: 2018
  • Doi Number: 10.1016/j.ijfatigue.2018.04.026
  • Title of Journal : International Journal of Fatigue
  • Page Numbers: pp.34-50
  • Keywords: Fatigue crack growth life, Fatigue crack growth path, Variable amplitude loading, XFEM

Abstract

© 2018 Elsevier LtdIn the present paper, a mesh independent computational algorithm is developed and incorporated into a commercial finite element software (Abaqus) for automated fatigue crack growth analysis under mixed mode variable amplitude loading conditions. The algorithm calculates the stress intensity factor (SIF) at predetermined small crack growth increments in the finite element software by using Extended Finite Element Method (XFEM) and predict the fatigue crack growth (FCG) path through local symmetry (KII=0) criterion. The aforementioned algorithm also computes the FCG life by means of cycle-by-cycle integration method through Nasgro equation based on the equivalent SIF range. Load history effects are also taken into account by using appropriate retardation models according to nature of the loading. For verification purpose, experimental crack path trajectories and fatigue life data available in the open literature are compared with computational results. Quite good agreements are obtained between the computed and the experimental results.