Long fatigue life critical crack lengths
ABSTRACT A model based on surface strain redistribution and crack closure is presented for prediction of the endurance or fatigue limit stress by determining the threshold stress and critical length of short cracks that develop under microstructural control. The threshold stress first decreases with...
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Published in | Fatigue & fracture of engineering materials & structures Vol. 33; no. 5; pp. 320 - 330 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.05.2010
Blackwell Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | ABSTRACT
A model based on surface strain redistribution and crack closure is presented for prediction of the endurance or fatigue limit stress by determining the threshold stress and critical length of short cracks that develop under microstructural control. The threshold stress first decreases with crack size to a local minimum then increases to a local maximum corresponding to the fatigue limit stress. This occurs at the critical crack length corresponding to about four grain diameters. The model is capable of determining the threshold stress range and depth of propagating and non‐propagating surface cracks as a function of stress ratio, material and grain size. The microstructure is shown to be particularly significant in the very long life regime (Nf ≈ 109 cycles). When the surface cracks become non‐propagating, internally initiated cracks continue growing slowly, eventually reaching the critical crack length with failure occurring after a very high number of cycles (107 < Nf < 109 cycles). |
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Bibliography: | ArticleID:FFE1444 ark:/67375/WNG-WP9213B9-C This manuscript was originally compiled for a Special Issue by Prof. C. Rodopoulos entitled 'Physics of Fatigue Damage'. istex:848B75D0257CD032D463BAFBFAC132F81CD54EE7 This manuscript was originally compiled for a Special Issue by Prof. C. Rodopoulos entitled ‘Physics of Fatigue Damage’. ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 8756-758X 1460-2695 |
DOI: | 10.1111/j.1460-2695.2010.01444.x |