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In-plane fracture analysis of paperboard using XFEM

Vojskovic, Daniel LU (2015) In TFHF-5202 FHL820 20151
Solid Mechanics
Abstract
It has been shown that during certain steps in the packaging process, the paperboard is prone to forming in-plane cracks. Hence, it is proposed to establish a model that can simulate failure in paperboard in order to get a better understanding of the mechanisms and ultimately, prevent any cracks from initiating.

The thesis begins with some introductory chapters which describes the background of the problem as well as the theory needed for the implementation. The implementation consists of two parts: the continuum model and the failure. Within the continuum model, two hardening functions are investigated and various size effects in the mechanical response, both from experiments and simulations, are examined and supported by new theory.... (More)
It has been shown that during certain steps in the packaging process, the paperboard is prone to forming in-plane cracks. Hence, it is proposed to establish a model that can simulate failure in paperboard in order to get a better understanding of the mechanisms and ultimately, prevent any cracks from initiating.

The thesis begins with some introductory chapters which describes the background of the problem as well as the theory needed for the implementation. The implementation consists of two parts: the continuum model and the failure. Within the continuum model, two hardening functions are investigated and various size effects in the mechanical response, both from experiments and simulations, are examined and supported by new theory. As for the failure model, which utilizes the cohesive zone model, a failure surface is established and two proposals of how to determinate the crack angle are investigated. This will be implemented in Abaqus 6.13 in FORTRAN language using the built in subroutines UMAT and UDMGINI as well as the pre-existing XFEM framework.

The result regarding only the continuum model was satisfying, although being unable to capture certain behaviour visible in the experiments, due to the influence of the out-of-plane behaviour. The failure model was showing similar results to the uniaxial experiments regarding crack angle, although being somewhat reluctant to initiate the crack, leading to a higher tensile stress. Therefore, a calibration was made against the uniaxial simulations before other geometries were examined. Also, the simulations were compared to the Digital Image Correlation images for the more complex geometries. (Less)
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author
Vojskovic, Daniel LU
supervisor
organization
course
FHL820 20151
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
In-plane failure, paperboard, XFEM, Abaqus 6.13, UMAT, UDMGINI, DIC, digital image correlation, FORTRAN, continuum model, Xia, modified Ramberg-Osgood, cohesive zone model, crack direction, softening, size effect
publication/series
TFHF-5202
language
English
id
7759008
date added to LUP
2016-08-19 14:20:56
date last changed
2016-08-19 14:20:56
@misc{7759008,
  abstract     = {It has been shown that during certain steps in the packaging process, the paperboard is prone to forming in-plane cracks. Hence, it is proposed to establish a model that can simulate failure in paperboard in order to get a better understanding of the mechanisms and ultimately, prevent any cracks from initiating.

The thesis begins with some introductory chapters which describes the background of the problem as well as the theory needed for the implementation. The implementation consists of two parts: the continuum model and the failure. Within the continuum model, two hardening functions are investigated and various size effects in the mechanical response, both from experiments and simulations, are examined and supported by new theory. As for the failure model, which utilizes the cohesive zone model, a failure surface is established and two proposals of how to determinate the crack angle are investigated. This will be implemented in Abaqus 6.13 in FORTRAN language using the built in subroutines UMAT and UDMGINI as well as the pre-existing XFEM framework.

The result regarding only the continuum model was satisfying, although being unable to capture certain behaviour visible in the experiments, due to the influence of the out-of-plane behaviour. The failure model was showing similar results to the uniaxial experiments regarding crack angle, although being somewhat reluctant to initiate the crack, leading to a higher tensile stress. Therefore, a calibration was made against the uniaxial simulations before other geometries were examined. Also, the simulations were compared to the Digital Image Correlation images for the more complex geometries.},
  author       = {Vojskovic, Daniel},
  keyword      = {In-plane failure,paperboard,XFEM,Abaqus 6.13,UMAT,UDMGINI,DIC,digital image correlation,FORTRAN,continuum model,Xia,modified Ramberg-Osgood,cohesive zone model,crack direction,softening,size effect},
  language     = {eng},
  note         = {Student Paper},
  series       = {TFHF-5202},
  title        = {In-plane fracture analysis of paperboard using XFEM},
  year         = {2015},
}