Publication detail
The effect of a free surface on fatigue crack behaviour
HUTAŘ, P. NÁHLÍK, L. KNÉSL, Z.
Czech title
Vliv volného povrchu na chování únavové trhliny
English title
The effect of a free surface on fatigue crack behaviour
Type
journal article - other
Language
en
Original abstract
The effect of a free surface on fatigue crack behaviour is discussed in the paper and generalized stress intensity factor methodology is used for a reliable estimation of the fatigue crack propagation rate in the area close to a free surface, where the effect of vertex singularity is important. It is shown that a decrease in the stress singularity exponent close to the vertex point leads to a decrease in the fatigue crack propagation rate and contributes to a typical curved crack front shape. The numerical estimations of the crack shape correspond well with experimental observations taken from the literature. Further change of the stress singularity exponent for thin structures was studied on M(T) specimens with different thicknesses. The proposed methodology facilitates explanation of the experimentally observed decrease in the fatigue crack propagation rate (FCPR) for thin structures. It is shown, that decrease of FCPR depends on Poisson's ratio and parameters of the Paris – Erdogan law for corresponding materials. These results can at least partially explain the effect of a free surface on fatigue crack behaviour and help towards a more reliable estimation of the residual fatigue lifetime of the structures considered.
Czech abstract
V práci je studováno chování únavové trhliny v blízkosti volného povrchu tělesa. Navrženým postupem je možné odhadnout nižší chychlost šíření únavové trhliny v blízkosti volného povrchu jenž vede k typickému zakřivení čela trhliny. Vypočítaná data jsou v dobrém souladu s experimentálními výsledky.
English abstract
The effect of a free surface on fatigue crack behaviour is discussed in the paper and generalized stress intensity factor methodology is used for a reliable estimation of the fatigue crack propagation rate in the area close to a free surface, where the effect of vertex singularity is important. It is shown that a decrease in the stress singularity exponent close to the vertex point leads to a decrease in the fatigue crack propagation rate and contributes to a typical curved crack front shape. The numerical estimations of the crack shape correspond well with experimental observations taken from the literature. Further change of the stress singularity exponent for thin structures was studied on M(T) specimens with different thicknesses. The proposed methodology facilitates explanation of the experimentally observed decrease in the fatigue crack propagation rate (FCPR) for thin structures. It is shown, that decrease of FCPR depends on Poisson's ratio and parameters of the Paris – Erdogan law for corresponding materials. These results can at least partially explain the effect of a free surface on fatigue crack behaviour and help towards a more reliable estimation of the residual fatigue lifetime of the structures considered.
Keywords in Czech
Rohová singularita; zobecněný součinitel intenzity napětí; singularita napětí; únavová trhlina; V-vrub
Keywords in English
Vertex singularity; Generalized stress intensity factor; Stress singularity; Fatigue crack; V-notch
RIV year
2010
Released
01.08.2010
Publisher
Elsevier
Location
Amsterdam
ISSN
0142-1123
Journal
INTERNATIONAL JOURNAL OF FATIGUE
Volume
32
Number
8
Pages from–to
1265–1269
Pages count
5
BIBTEX
@article{BUT49755,
author="Pavel {Hutař} and Luboš {Náhlík} and Zdeněk {Knésl},
title="The effect of a free surface on fatigue crack behaviour",
journal="INTERNATIONAL JOURNAL OF FATIGUE",
year="2010",
volume="32",
number="8",
month="August",
pages="1265--1269",
publisher="Elsevier",
address="Amsterdam",
issn="0142-1123"
}