Paper Titles
Analysis of Biaxial Fatigue Crack Growth in Microstructure Modeled by Voronoi-Polygon
p.211
Variability in Fatigue Behavior of a Zr-Based Bulk Metallic Glass (BMG) as a Result of Average Surface Roughness and Pronounced Surface Defects
p.217
Fatigue Behaviour of Extruded Mg2Si-Reinforced Magnesium Alloy
p.223
In-Situ Atomic Force Microscopy and Crystallo Graphic Orientation Analysis of Small Fatigue Crack Deflection Behavior
p.227
The Mechanism of Fatigue Crack Propagation
p.231
Coaxing Effect in Stainless Steels and High-Strength Steels
p.235
Microstructural Effects on Low Cycle Fatigue of Sn-3.8Ag-0.7Cu Pb-Free Solder
p.239
Evaluation of Fretting Fatigue Life for Steam Generator Tubes in Nuclear Power Plants
p.243
Fatigue Strength of Formable Ultra High-Strength TRIP-Aided Steels with Bainitic Ferrite Matrix
p.247

The Mechanism of Fatigue Crack Propagation

Article Preview

Abstract:

As a retardation of fatigue crack propagation occur under two step loading such as high to low loading, it is difficult to predictt the fatigue life in variable loading conditions. Therefore, the mechanism of retardation was investigated by changing the ratio of two step-loading in some materials in this paper. It is found in this study that when the ratio of low loading to high loading is less than 50 %, crack arrest occur in agreement with Elber’s formula about crack closure. We believe that crack closure phenomenon is the main problem in considering mechanism of crack propagation in the second stage. In this paper it is estimated that crack closure phenomenon arises because tensile plastic zone at crack tip is compressed by surrounding elastic zone. On the basis of the crack closure phenomenon, the mechanism of crack propagation in the second stage is proposed.

You might also be interested in these eBooks
The Mechanical Behavior of Materials X View Preview

Info:

Periodical:

Key Engineering Materials (Volumes 345-346)

Pages:

231-234

DOI:

https://doi.org/10.4028/www.scientific.net/KEM.345-346.231

Citation:

Cite this paper

Online since:

August 2007

Authors:

Katsuaki Furukawa

Keywords:

Crack Arrest, Crack Closure, Fatigue Crack Growth (FCG), Mechanism, Prediction of Fatigue Life, Retardation, Step Loading, Variable Amplitude

Export:

RIS, BibTeX

Price:

Permissions CCC:

Request Permissions

Permissions PLS:

Request Permissions

Сopyright:

© 2007 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

References

[1] W. Elber, The significance of fatigue crack closure, ASTM STP 486, pp.230-242 (1971).

Google Scholar

[2] H. Sehitoglu and D. L. McDiarmid , The effect of load step-down on fatigue crack arrest and retardation, International Journal of Fatigue, April, pp.55-60 (1980).

DOI: 10.1016/0142-1123(80)90032-8

Google Scholar

[3] D. L. McDiarmid, W. Choy and T.M. Lee, The effect of mean stress on delay in fatigue crack growth under load step-down, International Journal of Fatigue, Vol. 6, No. 2, April, pp.101-105(1984).

DOI: 10.1016/0142-1123(84)90020-3

Google Scholar

[4] D. Damri and J. F. Knott, Fatigue crack growth retardation in plane stress and plane strain, Journal of Materials Science, Vol. 26, pp.5613-5617 (1991).

DOI: 10.1007/pl00020432

Google Scholar

[5] J. C. Newman Jr., A. Brot and C. Matias, Crack-growth calculations in 7075-T7351 aluminum alloy under various load spectra using an improved crack-closure model, Engineering Fracture Mechanics, Vol. 71, pp.2347-2363 (2004).

DOI: 10.1016/j.engfracmech.2004.01.004

Google Scholar

[6] Ravindra Patankar and Asok Ray, State-space modeling of fatigue crack growth in ductile alloys, Engineering Fracture Mechanics, Vol. 66, pp.129-151 (2000).

DOI: 10.1016/s0013-7944(00)00010-2

Google Scholar