---
_id: '54282'
abstract:
- lang: eng
  text: <jats:title>Abstract</jats:title><jats:p>Stretching of polycarbonate films
    leads to the formation of shear bands in the necking zone [1]. Standard viscoplastic
    material models render mesh size dependent results, which requires a mathematical
    regularization. To this end, we present a finite strain gradient theory for a
    viscoplastic, isotropic material model where we extend the model presented in
    [2] to a micromorphic model by introducing a new micromorphic variable as an additional
    degree of freedom with its first gradient [3, 4]. The variable here has the meaning
    of a micro plastic strain, and is coupled with the macro plastic by a micro penalty
    term, forcing the macro‐plastic strain to be close to the micro‐plastic strain
    for the targeted shear band regularization effect. We have implemented the model
    equations as a three dimensional initial boundary value problem in an in house
    FE‐tool, to simulate different geometries with different thickness and to compare
    it the experimental tests. The analysis is performed for a uniaxial tensile geometry
    as well as for a biaxial tensile geometry. The numerical examples show the ability
    of the model to regularize the shear bands and solve the problem of localization.</jats:p>
author:
- first_name: Ayoub
  full_name: Hamdoun, Ayoub
  id: '57708'
  last_name: Hamdoun
- first_name: Rolf
  full_name: Mahnken, Rolf
  id: '335'
  last_name: Mahnken
citation:
  ama: Hamdoun A, Mahnken R. A finite strain gradient theory for viscoplasticity by
    means of micromorphic regularization. <i>PAMM</i>. 2023;22(1). doi:<a href="https://doi.org/10.1002/pamm.202200074">10.1002/pamm.202200074</a>
  apa: Hamdoun, A., &#38; Mahnken, R. (2023). A finite strain gradient theory for
    viscoplasticity by means of micromorphic regularization. <i>PAMM</i>, <i>22</i>(1).
    <a href="https://doi.org/10.1002/pamm.202200074">https://doi.org/10.1002/pamm.202200074</a>
  bibtex: '@article{Hamdoun_Mahnken_2023, title={A finite strain gradient theory for
    viscoplasticity by means of micromorphic regularization}, volume={22}, DOI={<a
    href="https://doi.org/10.1002/pamm.202200074">10.1002/pamm.202200074</a>}, number={1},
    journal={PAMM}, publisher={Wiley}, author={Hamdoun, Ayoub and Mahnken, Rolf},
    year={2023} }'
  chicago: Hamdoun, Ayoub, and Rolf Mahnken. “A Finite Strain Gradient Theory for
    Viscoplasticity by Means of Micromorphic Regularization.” <i>PAMM</i> 22, no.
    1 (2023). <a href="https://doi.org/10.1002/pamm.202200074">https://doi.org/10.1002/pamm.202200074</a>.
  ieee: 'A. Hamdoun and R. Mahnken, “A finite strain gradient theory for viscoplasticity
    by means of micromorphic regularization,” <i>PAMM</i>, vol. 22, no. 1, 2023, doi:
    <a href="https://doi.org/10.1002/pamm.202200074">10.1002/pamm.202200074</a>.'
  mla: Hamdoun, Ayoub, and Rolf Mahnken. “A Finite Strain Gradient Theory for Viscoplasticity
    by Means of Micromorphic Regularization.” <i>PAMM</i>, vol. 22, no. 1, Wiley,
    2023, doi:<a href="https://doi.org/10.1002/pamm.202200074">10.1002/pamm.202200074</a>.
  short: A. Hamdoun, R. Mahnken, PAMM 22 (2023).
date_created: 2024-05-14T09:06:38Z
date_updated: 2024-05-14T09:15:38Z
doi: 10.1002/pamm.202200074
intvolume: '        22'
issue: '1'
language:
- iso: eng
publication: PAMM
publication_identifier:
  issn:
  - 1617-7061
  - 1617-7061
publication_status: published
publisher: Wiley
status: public
title: A finite strain gradient theory for viscoplasticity by means of micromorphic
  regularization
type: journal_article
user_id: '57708'
volume: 22
year: '2023'
...