Premium
Stepwise S‐N curve and fish‐eye failure in gigacycle fatigue
Author(s) -
Nishijima,
Kanazawa
Publication year - 1999
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1046/j.1460-2695.1999.00206.x
Subject(s) - materials science , fatigue testing , surface (topology) , fracture (geology) , facet (psychology) , failure mode and effects analysis , composite material , fatigue limit , stress (linguistics) , structural engineering , engineering , geometry , mathematics , psychology , social psychology , linguistics , philosophy , personality , big five personality traits
Fatigue failure is normally initiated at the surface of a material. For some materials, failure can be initiated both at the surface and the interior. This twofold materials behaviour in fatigue is represented by a stepwise shape in the S – N curve. An internal failure mode is especially important for fatigue life in the gigacycle range, as this mode is predominant at low stress ranges. Materials with a hardened surface fail from the surface only at high stresses, and at low stresses from the inside, forming a fish‐eye facet on the fracture surface. Exactly the same behaviour can be observed for materials without a hard surface, even at elevated temperatures. This paper displays some of the results obtained at NRIM and discusses possible interpretations.