miun.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Modeling rapidly growing cracks in planar materials with a view to micro structural effects
Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.ORCID iD: 0000-0002-2066-5486
Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
2015 (English)In: International Journal of Fracture, ISSN 0376-9429, E-ISSN 1573-2673, Vol. 192, no 2, 191-201 p.Article in journal (Refereed) Published
Abstract [en]

Dynamic fracture behavior in both fairly continuous materials and discontinuous cellular materials is analyzed using a hybrid particle model. It is illustrated that the model remarkably well captures the fracture behavior observed in experiments on fast growing cracks reported elsewhere. The material's microstructure is described through the configuration and connectivity of the particles and the model's sensitivity to a perturbation of the particle configuration is judged. In models describing a fairly homogeneous continuous material, the microstructure is represented by particles ordered in rectangular grids, while for models describing a discontinuous cellular material, the microstructure is represented by particles ordered in honeycomb grids having open cells. It is demonstrated that small random perturbations of the grid representing the microstructure results in scatter in the crack growth velocity. In materials with a continuous microstructure, the scatter in the global crack growth velocity is observable, but limited, and may explain the small scattering phenomenon observed in experiments on high-speed cracks in e.g. metals. A random perturbation of the initially ordered rectangular grid does however not change the average macroscopic crack growth velocity estimated from a set of models having different grid perturbations and imply that the microstructural discretization is of limited importance when predicting the global crack behavior in fairly continuous materials. On the other hand, it is shown that a similar perturbation of honeycomb grids, representing a material with a discontinuous cellular microstructure, result in a considerably larger scatter effect and there is also a clear shift towards higher crack growth velocities as the perturbation of the initially ordered grid become larger. Thus, capturing the discontinuous microstructure well is important when analyzing growing cracks in cellular or porous materials such as solid foams or wood.

Place, publisher, year, edition, pages
2015. Vol. 192, no 2, 191-201 p.
Keyword [en]
Crack growth velocity, Dynamic fracture, Heterogeneous material, Particle method
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:miun:diva-24958DOI: 10.1007/s10704-015-0002-9ISI: 000352711800005Scopus ID: 2-s2.0-84939958015OAI: oai:DiVA.org:miun-24958DiVA: diva2:813571
Funder
Swedish Research Council, 2010- 4348
Available from: 2015-05-23 Created: 2015-05-23 Last updated: 2016-12-16Bibliographically approved
In thesis
1. On dynamic crack growth in discontinuous materials
Open this publication in new window or tab >>On dynamic crack growth in discontinuous materials
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis work numerical procedures are developed for modeling dynamic fracture of discontinuous materials, primarily materials composed of a load-bearing network. The models are based on the Newtonian equations of motion, and does not require neither stiffness matrices nor remeshing as cracks form and grow. They are applied to a variety of cases and some general conclusions are drawn. The work also includes an experimental study of dynamic crack growth in solid foam. The aims are to deepen the understanding of dynamic fracture by answering some relevant questions, e.g. What are the major sources of dissipation of potential energy in dynamic fracture? What are the major differences between the dynamic fracture in discontinuous network materials as compared to continuous materials? Is there any situation when it would be possible to utilize a homogenization scheme to model network materials as continuous? The numerical models are compared with experimental results to validate their ability to capture the relevant behavior, with good results. The only two plausible dissipation mechanisms are energy spent creating new surfaces, and stress waves, where the first dominates the behavior of slow cracks and the later dominates fast cracks. In the numerical experiments highly connected random fiber networks, i.e. structures with short distance between connections, behaves phenomenologically like a continuous material whilst with fewer connections the behavior deviates from it. This leads to the conclusion that random fiber networks with a high connectivity may be treated as a continuum, with appropriately scaled material parameters. Another type of network structures is the ordered networks, such as honeycombs and semi-ordered such as foams which can be viewed as e.g. perturbed honeycomb grids. The numerical results indicate that the fracture behavior is different for regular honeycombs versus perturbed honeycombs, and the behavior of the perturbed honeycomb corresponds well with experimental results of PVC foam.

Place, publisher, year, edition, pages
Sundsvall: Mittuniversitetet, 2015. 20 p.
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 223
National Category
Engineering and Technology Natural Sciences
Identifiers
urn:nbn:se:miun:diva-24960 (URN)978-91-88025-26-5 (ISBN)
Public defence
2015-06-16, Sundsvall, 09:15
Opponent
Supervisors
Available from: 2015-05-25 Created: 2015-05-23 Last updated: 2015-05-25Bibliographically approved

Open Access in DiVA

fulltext(1076 kB)25 downloads
File information
File name FULLTEXT01.pdfFile size 1076 kBChecksum SHA-512
4a287a6123768544d7fa47b0ef38ac289537f3374e4b0331a55e8638248391b5efcd41b0af34946270882067f57162dd22eecd1ba3a11c3d4b119a5ad28e4559
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Persson, JohanPer, Isaksson
By organisation
Department of Natural Sciences
In the same journal
International Journal of Fracture
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 25 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 73 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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