The Open Materials Science Journal

2008, 2 : 35-39
Published online 2008 July 4. DOI: 10.2174/1874088X00802010035
Publisher ID: TOMSJ-2-35

Propagation Lifetime from the Surface and Internal Defects in the Ultra High Cycle Fatigue Regime

Yves Nadot
Laboratoire de Mécanique et de Physique des Matériaux, UMR CNRS 6617, ENSMA, 1 avenue Clément Ader, Téléport 2, BP 40 109, 86 961 Futuroscope cedex, France.

ABSTRACT

Ultra High Cycle fatigue leads to a failure initiated in the bulk material of a material. Some results on the nodular cast iron are presented: initiation occurs from the defects, located at the surface or in the bulk. It has been shown that environment plays a major role that could explain the difference between fatigue lives, for the surface and internal initiation. The influence of the defect size and crack growth law is discussed and, the importance of fatigue crack initiation stage is revealed, in the ultra high cycle regime

Keywords:

Casting, high cycle fatigue, environmental effect.