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
An experimental method for estimating the tearing energy inrubber-like materials using the true stored energy
KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
2015 (English)Report (Other academic)
Abstract [en]

A method for determining the critical tearing energy in rubber-like materials is proposed. In this method, the energy required for crack propagation in a rubber-like material is determined by the change of the recovered elastic energy. Hence, the dissipated energy due to different inelastic processes is deducted from the total strain energy applied to a system. Therefore, the classical method proposed by Rivlin and Thomas (Rivlin and Thomas in Journal of Polymer Science 10(3):291-318,1953) using the pure shear tear test is modified using the actual stored elastic energy. The elastically stored energy in a pure shear is determined experimentally using cyclic loading. The experimental results show that the classical method overestimates the critical tearing energy by approximately $15\%$. Moreover, the effect of the unloading rate on the determination of the elastically stored energy is investigated and found to be minimal suggesting that the crack propagation velocity has a minor effect in the change of the elastically stored energy.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2015.
Series
TRITA-HFL. Report / Royal Institute of Technology, Solid Mechanics, ISSN 1654-1472 ; 580
National Category
Other Materials Engineering
Identifiers
URN: urn:nbn:se:kth:diva-178050OAI: oai:DiVA.org:kth-178050DiVA: diva2:876370
Note

QC 20151203

Available from: 2015-12-03 Created: 2015-12-03 Last updated: 2016-03-01Bibliographically approved
In thesis
1. Modeling of fracture and damage in rubber under dynamic and quasi-static conditions
Open this publication in new window or tab >>Modeling of fracture and damage in rubber under dynamic and quasi-static conditions
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Elastomers are important engineering materials that have contributed to the different technical developments and applications since the 19th century. The study of crack growth mechanics for elastomers is of great importance to produce reliable products and therefore costly failures can be prevented. On the other hand, it is fundamental in some applications such as adhesion technology, elastomers wear, etc. In this thesis work, crack propagation in rubber under quasi-static and dynamic conditions is investigated.

In Paper A, theoretical and computational frameworks for dynamic crack propagation in rubber have been developed. The fracture separation process is presumed to be described by a cohesive zone model and the bulk behavior is assumed to be determined by viscoelasticity theory. The numerical model is able to predict the dynamic crack growth. Further, the viscous dissipation in the continuum is found to be negligible and the strength and the surface energy vary with the crack speed. Hence, the viscous contribution in the innermost of the crack tip has been investigated in Paper B. This contribution is incorporated using a rate-dependent cohesive model. The results suggest that the viscosity varies with the crack speed. Moreover, the estimation of the total work of fracture shows that the fracture-related processes contribute to the total work of fracture in a contradictory manner.

A multiscale continuum model of strain-induced cavitation damage and crystallization in rubber-like materials is proposed in Paper C. The model adopts the network decomposition concept and assumes the interaction between the filler particles and long-chain molecules results in two networks between cross-links and between the filler aggregates. The network between the crosslinks is assumed to be semi-crystalline, and the network between the filler aggregates is assumed to be amorphous with the possibility of debonding. Moreover, the material is assumed to be initially non-cavitated and the cavitation may take place as a result from the debonding process. The cavities are assumed to exhibit growth phase that may lead to complete damage. The comparison with the experimental data from the literature shows that the model is capable to predict accurately the experimental data.

Papers D and E are dedicated to experimental studies of the crack propagation in rubber. A new method for determining the critical tearing energy in rubber-like materials is proposed in Paper D. The method attempts to provide an accurate prediction of the tearing energy by accounting for the dissipated energy due to different inelastic processes. The experimental results show that classical method overestimates the critical tearing energy by approximately 15%. In Paper E, the fracture behavior of carbon-black natural rubber material is experimentally studied over a range of loading rates varying from quasi-static to dynamic, different temperatures, and fracture modes. The tearing behavior shows a stick-slip pattern in low velocities with a size dependent on the loading rate, temperature and the fracture mode. Smooth propagation results at high velocities. The critical tearing depends strongly on the loading rate as well as the temperature.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. xv, 37 p.
Series
TRITA-HFL. Report / Royal Institute of Technology, Solid Mechanics, ISSN 1654-1472 ; 0581
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:kth:diva-178048 (URN)978-91-7595-749-4 (ISBN)
Public defence
2015-12-18, sal B2, Brinellvägen 23 (02 tr), KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20150203

Available from: 2015-12-03 Created: 2015-12-03 Last updated: 2015-12-31Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Elmukashfi, Elsiddig
By organisation
Solid Mechanics (Div.)
Other Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 143 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