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Evaluation of Hoffman and Xia plasticity models against bi-axial tension experiments of planar fiber network materials

Alzweighi, Mossab ; Mansour, Rami ; Tryding, Johan LU and Kulachenko, Artem (2022) In International Journal of Solids and Structures 238.
Abstract

The anisotropic properties and pressure sensitivity are intrinsic features of the constitutive response of fiber network materials. Although advanced models have been developed to simulate the complex response of fibrous materials, the lack of comparative studies may lead to a dubiety regarding the selection of a suitable method. In this study, the pressure-sensitive Hoffman yield criterion and the Xia model are implemented for the plane stress case to simulate the mechanical response under a bi-axial loading state. The performance of both models is experimentally assessed by comparison to bi-axial tests on cruciform-shaped specimens loaded in different directions with respect to the material principal directions. The comparison with... (More)

The anisotropic properties and pressure sensitivity are intrinsic features of the constitutive response of fiber network materials. Although advanced models have been developed to simulate the complex response of fibrous materials, the lack of comparative studies may lead to a dubiety regarding the selection of a suitable method. In this study, the pressure-sensitive Hoffman yield criterion and the Xia model are implemented for the plane stress case to simulate the mechanical response under a bi-axial loading state. The performance of both models is experimentally assessed by comparison to bi-axial tests on cruciform-shaped specimens loaded in different directions with respect to the material principal directions. The comparison with the experimentally measured forces shows the ability of the Hoffman model as well as the Xia model with shape parameter k≤2 to adequately predict the material response. However, this study demonstrates that the Xia model consistently presents a stiffer bi-axial response when k≥3 compared to the Hoffman model. This result highlights the importance of calibrating the shape parameter k for the Xia model using a bi-axial test, which can be a cumbersome task. Also, for the same tension-compression response, the Hill criterion as a special case of the Hoffman model presents a good ability to simulate the mechanical response of the material for bi-axial conditions. Furthermore, in terms of stability criteria, the Xia model is unconditionally convex while the convexity of the Hoffman model is a function of the orthotropic plastic matrix. This study not only assesses the prediction capabilities of the two models, but also gives an insight into the selection of an appropriate constitutive model for material characterization and simulation of fibrous materials. The UMAT implementations of both models which are not available in commercial software and the calibration tool of the Xia model are shared with open-source along with this work.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bi-axial loading, Continuum modeling, Fiber network, Hill criterion, Hoffman criterion, Pressure sensitivity, UMAT implementations, Xia model
in
International Journal of Solids and Structures
volume
238
article number
111358
publisher
Elsevier
external identifiers
  • scopus:85121230891
ISSN
0020-7683
DOI
10.1016/j.ijsolstr.2021.111358
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2021 The Author(s)
id
00d9ebf8-3557-4487-966b-533daeefc681
date added to LUP
2022-01-27 10:59:30
date last changed
2022-04-19 19:29:17
@article{00d9ebf8-3557-4487-966b-533daeefc681,
  abstract     = {{<p>The anisotropic properties and pressure sensitivity are intrinsic features of the constitutive response of fiber network materials. Although advanced models have been developed to simulate the complex response of fibrous materials, the lack of comparative studies may lead to a dubiety regarding the selection of a suitable method. In this study, the pressure-sensitive Hoffman yield criterion and the Xia model are implemented for the plane stress case to simulate the mechanical response under a bi-axial loading state. The performance of both models is experimentally assessed by comparison to bi-axial tests on cruciform-shaped specimens loaded in different directions with respect to the material principal directions. The comparison with the experimentally measured forces shows the ability of the Hoffman model as well as the Xia model with shape parameter k≤2 to adequately predict the material response. However, this study demonstrates that the Xia model consistently presents a stiffer bi-axial response when k≥3 compared to the Hoffman model. This result highlights the importance of calibrating the shape parameter k for the Xia model using a bi-axial test, which can be a cumbersome task. Also, for the same tension-compression response, the Hill criterion as a special case of the Hoffman model presents a good ability to simulate the mechanical response of the material for bi-axial conditions. Furthermore, in terms of stability criteria, the Xia model is unconditionally convex while the convexity of the Hoffman model is a function of the orthotropic plastic matrix. This study not only assesses the prediction capabilities of the two models, but also gives an insight into the selection of an appropriate constitutive model for material characterization and simulation of fibrous materials. The UMAT implementations of both models which are not available in commercial software and the calibration tool of the Xia model are shared with open-source along with this work.</p>}},
  author       = {{Alzweighi, Mossab and Mansour, Rami and Tryding, Johan and Kulachenko, Artem}},
  issn         = {{0020-7683}},
  keywords     = {{Bi-axial loading; Continuum modeling; Fiber network; Hill criterion; Hoffman criterion; Pressure sensitivity; UMAT implementations; Xia model}},
  language     = {{eng}},
  month        = {{03}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Solids and Structures}},
  title        = {{Evaluation of Hoffman and Xia plasticity models against bi-axial tension experiments of planar fiber network materials}},
  url          = {{http://dx.doi.org/10.1016/j.ijsolstr.2021.111358}},
  doi          = {{10.1016/j.ijsolstr.2021.111358}},
  volume       = {{238}},
  year         = {{2022}},
}