Paper Titles
Preface
Fatigue Failure under Varying Loading within Fatigue Limit Diagram
p.1
Overview of Fatigue Behaviour of Ultrafine-Grained Copper Produced by Severe Plastic Deformation
p.9
Modeling of Cracks Crossing an Interface between Dissimilar Elastic Anisotropic Materials
p.17
Microstructural Parameters in the Theory of Critical Distances
p.23
Plastic Deformation of Metallic Nanostructures
p.29
Influence of Phosphorus Grain Boundary Segregation on Fracture Behaviour of Iron-Base Alloys
p.33
Experimental Techniques in Fracture Characterization
p.39
Solute and Temperature Effects on the Strain Hardening Behaviour of Mg-Zn Solid Solutions
p.45

Fatigue Failure under Varying Loading within Fatigue Limit Diagram

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Abstract:

Although fatigue limit diagram is defined in principle for constant stress amplitude condition, it is often considered that fatigue failure would not occur even in varying loading if applied stresses were kept within the fatigue limit diagram. However, it was shown in the case of small-notched specimen and fretting fatigue that fatigue failure occurred in some special case of variable amplitude loading condition even when all stress amplitudes were kept within the fatigue limit diagram. The cause of this phenomenon was examined using two-step and repeated two-step stress patterns in which the first step stress was with zero mean stress and the second step stress had a high mean stress. A non-propagating crack was formed by the first step stress. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure occurred even when all stress amplitudes were kept within the fatigue limit diagram. It was an unexpected fracture caused by the interference effect of non-propagating crack and mean stress change.

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Periodical:

Materials Science Forum (Volumes 567-568)

Pages:

1-8

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.567-568.1

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Online since:

December 2007

Authors:

Yoshiyuki Kondo, H. Eda, Masanobu Kubota

Keywords:

Fatigue, Fatigue Limit Diagram, Fretting Fatigue, Non-Propagating Crack, Varying Load

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© 2008 Trans Tech Publications Ltd. All Rights Reserved

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References

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