Numerical estimation of the fatigue crack front shape for a specimen with finite thickness

0385371 - ÚFM 2013 RIV GB eng J - Journal Article
Ševčík, Martin - Hutař, Pavel - Zouhar, Michal - Náhlík, Luboš
Numerical estimation of the fatigue crack front shape for a specimen with finite thickness.
International Journal of Fatigue. Roč. 39, č. 1 (2012), s. 75-80. ISSN 0142-1123. E-ISSN 1879-3452
R&D Projects: GA ČR GA101/09/0867; GA ČR GA106/09/1954
Institutional research plan: CEZ:AV0Z2041904
Keywords : Crack front shape * Vertex singularity * Fatigue crack * Stress singularity exponent
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 1.976, year: 2012

An iterative process for the estimation of a fatigue crack front based on linear elastic fracture mechanics using values of the stress singularity exponent is presented. Based on the assumption of a constant stress singularity exponent along the crack front, a numerical approach leading to crack shape determination is suggested and applied. The crack front was approximated by a spline curve. In each node defining the crack front the stress singularity exponent was estimated and a complete crack front shape was found. The difference between thin and thick specimens is then described and discussed. The approach presented leads to better estimation of the crack front shape for structures with different thicknesses and a more accurate determination of fatigue crack fracture parameters. The results presented can be helpful for a better understanding of fatigue failure and more reliable prediction of residual lifetime.
Permanent Link: http://hdl.handle.net/11104/0214639