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Dissolution driven crack branching in polycarbonate

Hejman, U. and Bjerkén, Christina LU (2011) In Fatigue & Fracture of Engineering Materials & Structures 34(4). p.227-239
Abstract
Stress corrosion, in the form of chemically assisted crack growth, in polycarbonate is examined with focus on crack branching characteristics. Cracks with finite width are observed; this is to be expected for dissolution driven cracking. The cracks branched repeatedly and crack widths before and after branching are measured. Both symmetric and asymmetric branching is found. The dissolution rate is assumed to be a linear function of the strain along the crack surface. In the literature, it is proposed that the crack width is proportional to the square of the mode I stress intensity factor. Energy considerations lead to that the sum of branch widths must equal the width of the unbranched crack. The results from this study correspond fairly... (More)
Stress corrosion, in the form of chemically assisted crack growth, in polycarbonate is examined with focus on crack branching characteristics. Cracks with finite width are observed; this is to be expected for dissolution driven cracking. The cracks branched repeatedly and crack widths before and after branching are measured. Both symmetric and asymmetric branching is found. The dissolution rate is assumed to be a linear function of the strain along the crack surface. In the literature, it is proposed that the crack width is proportional to the square of the mode I stress intensity factor. Energy considerations lead to that the sum of branch widths must equal the width of the unbranched crack. The results from this study correspond fairly well with this assumption. The branching angle is found to be 32 degrees +/- 12 degrees, which is in line with results for sharp cracks reported in the literature. The mean growth direction of the branches is found to deviate slightly from the expected straight. No significant correlation between angles and crack widths is found. The scatter in results is mainly addressed to the inherent perturbation sensitivity of stress corrosion cracking. Also numerically simulations of crack branching is performed. These results show promising agreement with the experiments. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
branching, dissolution, experiment, finite element modelling, polycarbonate, stress corrosion cracking
in
Fatigue & Fracture of Engineering Materials & Structures
volume
34
issue
4
pages
227 - 239
publisher
Wiley-Blackwell
external identifiers
  • wos:000288127600001
  • scopus:79952555249
ISSN
1460-2695
DOI
10.1111/j.1460-2695.2010.01508.x
language
English
LU publication?
yes
id
c8b4ac6f-13dc-4dbb-9824-1b91e1a21895 (old id 1868498)
date added to LUP
2011-04-19 12:24:21
date last changed
2017-10-01 03:00:19
@article{c8b4ac6f-13dc-4dbb-9824-1b91e1a21895,
  abstract     = {Stress corrosion, in the form of chemically assisted crack growth, in polycarbonate is examined with focus on crack branching characteristics. Cracks with finite width are observed; this is to be expected for dissolution driven cracking. The cracks branched repeatedly and crack widths before and after branching are measured. Both symmetric and asymmetric branching is found. The dissolution rate is assumed to be a linear function of the strain along the crack surface. In the literature, it is proposed that the crack width is proportional to the square of the mode I stress intensity factor. Energy considerations lead to that the sum of branch widths must equal the width of the unbranched crack. The results from this study correspond fairly well with this assumption. The branching angle is found to be 32 degrees +/- 12 degrees, which is in line with results for sharp cracks reported in the literature. The mean growth direction of the branches is found to deviate slightly from the expected straight. No significant correlation between angles and crack widths is found. The scatter in results is mainly addressed to the inherent perturbation sensitivity of stress corrosion cracking. Also numerically simulations of crack branching is performed. These results show promising agreement with the experiments.},
  author       = {Hejman, U. and Bjerkén, Christina},
  issn         = {1460-2695},
  keyword      = {branching,dissolution,experiment,finite element modelling,polycarbonate,stress corrosion cracking},
  language     = {eng},
  number       = {4},
  pages        = {227--239},
  publisher    = {Wiley-Blackwell},
  series       = {Fatigue & Fracture of Engineering Materials & Structures},
  title        = {Dissolution driven crack branching in polycarbonate},
  url          = {http://dx.doi.org/10.1111/j.1460-2695.2010.01508.x},
  volume       = {34},
  year         = {2011},
}