Malmö University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Branching of growing corrosion fatigue cracks
Malmö högskola, School of Technology (TS).ORCID iD: 0000-0002-7952-5330
Malmö högskola, School of Technology (TS).
2005 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Strain-driven corrosion of branching cracks, initiated from a virtually plane surface, has been studied using a moving boundary technique. The material is assumed linear elastic and is subjected to fatigue loading under plain strain conditions. The surface of the material is covered by a protective film. During loading this film can be damaged if it is strained above a threshold value, thus revealing an unprotected surface. Corrosion advances by material dissolution, eventually evolving into cracks. The rate of surface evolution is a function of the degree of protective film damage. During unloading the protective film is assumed to develop and heal the surface. A low frequency cyclic loading is applied to ensure that total healing is assumed. The moving boundary technique, simulating corrosion, results in arc-shaped crack tips, rather than singular crack tip points, thus no crack growth criterion is needed in the analysis. For each load step, the strain distribution is found using the finite element method, followed by required the movement the boundary and then remeshing. The crack growth has been investigated for at least 2000 cycles. A more or less pronounced branching of the cracks is found to develop. The crack branches can be classified in three groups; main cracks that grows with maximum rate and branches further, branch cracks that initially retards and then find a steady state growth rate that is a fraction of maximum speed, and finally, arresting cracks that after a period of retardation stop growing. The crack patterns are realistic, showing a sort of self-similarity with tree-like structure, cf. the picture below that shows a typical finite element result. The width of a crack branch together with the shielding from the applied stresses, caused by the other branches and main cracks, seem to govern the evolution of the crack branch. A steady-state growth rate is achieved during parts of the evolution as the crack width and the strain field surrounding the crack tip is in balance, i.e. the crack widens while the crack grows longer. As the bluntness of the tip reaches an upper limit, branching results.

Place, publisher, year, edition, pages
2005.
National Category
Applied Mechanics
Identifiers
URN: urn:nbn:se:mau:diva-12361Local ID: 10396OAI: oai:DiVA.org:mau-12361DiVA, id: diva2:1409408
Conference
Irish Mechanics Society, Dublin, Irland (2005)
Available from: 2020-02-29 Created: 2020-02-29 Last updated: 2022-06-27Bibliographically approved

Open Access in DiVA

No full text in DiVA

Authority records

Bjerkén, ChristinaStåhle, Per

Search in DiVA

By author/editor
Bjerkén, ChristinaStåhle, Per
By organisation
School of Technology (TS)
Applied Mechanics

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 27 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf