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In-Plane Fracture of Paper

Tryding, Johan LU (1996) In Report TVSM 1008.
Abstract (Swedish)
Popular Abstract in Swedish

Pappersbrott i planet har studerats med hjälp av den kohesiva sprick modellen ur ett experimentellt såväl som ur ett teoretiskt perspektiv.



Brott i en pappersremsa erhålls när remsan i en provmaskin belastas till sin maximala bärlast. Om remsan är tillräckligt kort fås en stabil nedåtgående last-förlängnigs kurva efter det att max lasten är nådd. Det visade sig att den stabila nedåtgående last-förlängnigs kurvan är beroende av i vilken riktning som remsan har klipps ut ur papperet.



Den stabila nedåtgående last-förlängnigs kurvan kan skrivas om till en stabila nedåtgående spännings-sprick förlängnigs kurva. Den nedåtgående spännings-sprick förlängnigs kurvan... (More)
Popular Abstract in Swedish

Pappersbrott i planet har studerats med hjälp av den kohesiva sprick modellen ur ett experimentellt såväl som ur ett teoretiskt perspektiv.



Brott i en pappersremsa erhålls när remsan i en provmaskin belastas till sin maximala bärlast. Om remsan är tillräckligt kort fås en stabil nedåtgående last-förlängnigs kurva efter det att max lasten är nådd. Det visade sig att den stabila nedåtgående last-förlängnigs kurvan är beroende av i vilken riktning som remsan har klipps ut ur papperet.



Den stabila nedåtgående last-förlängnigs kurvan kan skrivas om till en stabila nedåtgående spännings-sprick förlängnigs kurva. Den nedåtgående spännings-sprick förlängnigs kurvan ligger som bas för utvecklade av en teoretisk modell för papersbrott. Den teoretisk modell har programerats in som en användar rutin i finita element programmet ABAQUS.



Finita element programmet ABAQUS med den nyutvecklade användarrutinen används för att nummeriskt simulera hur en pappersbit med en centalt belägen spricka spricker upp under dragbelastning. De numeriska simuleringarna har jämförts med experimentella resultat och god överensstämmelse har observerats. (Less)
Abstract
The in-plane failure of paper is studied in this work by means of a cohesive crack model from experimental as well as theoretical perspectives.



Localized damage at in-plane tension of short paper strips is studied for low strain rates. It is observed that under uniaxial in-plane tensile tests, the evolution of the failure is stable and the damage of the paper strip is localized into a narrow zone. The damage in the paper strip develops only after the tensile strength has been reached. The uniaxial fracture properties of paper are defined and characterized by a descending stress-crack widening curve. From this curve the fracture energy can be obtained. A characteristic material parameter of a length dimension is... (More)
The in-plane failure of paper is studied in this work by means of a cohesive crack model from experimental as well as theoretical perspectives.



Localized damage at in-plane tension of short paper strips is studied for low strain rates. It is observed that under uniaxial in-plane tensile tests, the evolution of the failure is stable and the damage of the paper strip is localized into a narrow zone. The damage in the paper strip develops only after the tensile strength has been reached. The uniaxial fracture properties of paper are defined and characterized by a descending stress-crack widening curve. From this curve the fracture energy can be obtained. A characteristic material parameter of a length dimension is introduced and depends on the fracture energy, the elastic modulus and the fracture strength. The material parameters are found to vary with the material orientation of the paper. A method to measure the fracture material parameters is proposed, where only the load and the elongation of the test specimen need to be recorded. Newsprint, kraft paper and paperboard are examined in this investigation.



The cohesive crack model is used as a basis in the formulation of an orthotropic smeared crack constitutive relation to be used in finite element codes. The advantage of this approach is that it provides a theoretical tool in the study of the initiation and stable growth of a localized damage zone or crack in an arbitrary structure subjected to an arbitrary in-plane loading. The model proposed includes a failure criterion and a failure potential. The failure criterion changes its size and shape during the course of fracture softening. The failure potential determines the orientation of the fracture zone and the subsequent crack. The cohesive crack constitutive model is calibrated against one newsprint and one board paper. Simulation results from a single central notch specimen loaded in mode I are compared with experimental results. It was found that the fracture process region is of significant size and that the deviation from an autonomous fracture performance is considerable.



The constitutive model developed is used in the investigation of the behavior of a fiber-based package material, with a punched opening, in the converting process at constant web tension. Finite element simulations of the converting process are made in order to understand how punched paperboard behaves in converting processes. The simulations are compared with experimental results and a reasonable agreement is obtained. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Carlsson, Leif A., Florida Atlantic University, USA
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Byggnadsteknik, Building construction, Paper, Fracture energy, Strain softening, Localized damage, Fracture mechanics
in
Report TVSM
volume
1008
pages
148 pages
publisher
Structural Mechanics, Lund University
defense location
Lärosal V:A
defense date
1997-01-20 10:15
external identifiers
  • Other:ISRN: LUTVDG/(TVSM-1008)/1-148/(1996)
ISBN
0281-6679
language
English
LU publication?
yes
id
00ed9825-776d-443a-a956-40fa254921f0 (old id 17671)
date added to LUP
2007-05-24 09:24:07
date last changed
2016-09-19 08:45:02
@misc{00ed9825-776d-443a-a956-40fa254921f0,
  abstract     = {The in-plane failure of paper is studied in this work by means of a cohesive crack model from experimental as well as theoretical perspectives.<br/><br>
<br/><br>
Localized damage at in-plane tension of short paper strips is studied for low strain rates. It is observed that under uniaxial in-plane tensile tests, the evolution of the failure is stable and the damage of the paper strip is localized into a narrow zone. The damage in the paper strip develops only after the tensile strength has been reached. The uniaxial fracture properties of paper are defined and characterized by a descending stress-crack widening curve. From this curve the fracture energy can be obtained. A characteristic material parameter of a length dimension is introduced and depends on the fracture energy, the elastic modulus and the fracture strength. The material parameters are found to vary with the material orientation of the paper. A method to measure the fracture material parameters is proposed, where only the load and the elongation of the test specimen need to be recorded. Newsprint, kraft paper and paperboard are examined in this investigation.<br/><br>
<br/><br>
The cohesive crack model is used as a basis in the formulation of an orthotropic smeared crack constitutive relation to be used in finite element codes. The advantage of this approach is that it provides a theoretical tool in the study of the initiation and stable growth of a localized damage zone or crack in an arbitrary structure subjected to an arbitrary in-plane loading. The model proposed includes a failure criterion and a failure potential. The failure criterion changes its size and shape during the course of fracture softening. The failure potential determines the orientation of the fracture zone and the subsequent crack. The cohesive crack constitutive model is calibrated against one newsprint and one board paper. Simulation results from a single central notch specimen loaded in mode I are compared with experimental results. It was found that the fracture process region is of significant size and that the deviation from an autonomous fracture performance is considerable.<br/><br>
<br/><br>
The constitutive model developed is used in the investigation of the behavior of a fiber-based package material, with a punched opening, in the converting process at constant web tension. Finite element simulations of the converting process are made in order to understand how punched paperboard behaves in converting processes. The simulations are compared with experimental results and a reasonable agreement is obtained.},
  author       = {Tryding, Johan},
  isbn         = {0281-6679},
  keyword      = {Byggnadsteknik,Building construction,Paper,Fracture energy,Strain softening,Localized damage,Fracture mechanics},
  language     = {eng},
  pages        = {148},
  publisher    = {ARRAY(0xdca76a0)},
  series       = {Report TVSM},
  title        = {In-Plane Fracture of Paper},
  volume       = {1008},
  year         = {1996},
}