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SEM study of overload effects during fatigue crack growth using an image analyzing technique and potential drop measures

Jacobsson, Lars LU ; Persson, Christer LU and Melin, Solveig LU (2010) In Fatigue & Fracture of Engineering Materials & Structures 33(2). p.105-115
Abstract
To study the mechanisms affecting the crack propagation rate for fatigue cracks exposed to an overload, an in situ scanning electron microscope technique was used, together with potential drop measurements. High-resolution images were analysed with an image analysis program to measure the displacements along the crack, and the potential drop technique was employed to measure the electrical contact between the fatigue crack surfaces. The crack closure level could, by image analysis, be determined as close as 1 μm from the crack tip. The indications from the image analysis pointed towards a somewhat lower closure load as compared to the potential drop technique. The effect of an overload on the crack propagation rate was found to depend on... (More)
To study the mechanisms affecting the crack propagation rate for fatigue cracks exposed to an overload, an in situ scanning electron microscope technique was used, together with potential drop measurements. High-resolution images were analysed with an image analysis program to measure the displacements along the crack, and the potential drop technique was employed to measure the electrical contact between the fatigue crack surfaces. The crack closure level could, by image analysis, be determined as close as 1 μm from the crack tip. The indications from the image analysis pointed towards a somewhat lower closure load as compared to the potential drop technique. The effect of an overload on the crack propagation rate was found to depend on the magnitude of the overload in combination with the steady-state conditions. Both overload induced crack retardation and crack acceleration was noticed to occur. [ABSTRACT FROM AUTHOR] (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
overload, Inconel 718, fatigue crack growth, image analysis, crack closure, scanning electron microscope
in
Fatigue & Fracture of Engineering Materials & Structures
volume
33
issue
2
pages
105 - 115
publisher
Wiley-Blackwell
external identifiers
  • wos:000273455900004
  • scopus:74849093737
ISSN
1460-2695
DOI
10.1111/j.1460-2695.2009.01421.x
language
English
LU publication?
yes
id
8b2446d8-913c-4115-a25a-51c36d56f7b4 (old id 1529677)
date added to LUP
2010-01-28 15:35:17
date last changed
2018-05-29 11:39:06
@article{8b2446d8-913c-4115-a25a-51c36d56f7b4,
  abstract     = {To study the mechanisms affecting the crack propagation rate for fatigue cracks exposed to an overload, an in situ scanning electron microscope technique was used, together with potential drop measurements. High-resolution images were analysed with an image analysis program to measure the displacements along the crack, and the potential drop technique was employed to measure the electrical contact between the fatigue crack surfaces. The crack closure level could, by image analysis, be determined as close as 1 μm from the crack tip. The indications from the image analysis pointed towards a somewhat lower closure load as compared to the potential drop technique. The effect of an overload on the crack propagation rate was found to depend on the magnitude of the overload in combination with the steady-state conditions. Both overload induced crack retardation and crack acceleration was noticed to occur. [ABSTRACT FROM AUTHOR]},
  author       = {Jacobsson, Lars and Persson, Christer and Melin, Solveig},
  issn         = {1460-2695},
  keyword      = {overload,Inconel 718,fatigue crack growth,image analysis,crack closure,scanning electron microscope},
  language     = {eng},
  number       = {2},
  pages        = {105--115},
  publisher    = {Wiley-Blackwell},
  series       = {Fatigue & Fracture of Engineering Materials & Structures},
  title        = {SEM study of overload effects during fatigue crack growth using an image analyzing technique and potential drop measures},
  url          = {http://dx.doi.org/10.1111/j.1460-2695.2009.01421.x},
  volume       = {33},
  year         = {2010},
}