article published Ayoub Hamdoun author 57708 Rolf Mahnken author 335 <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> Wiley2023 eng 1617-7061 1617-706110.1002/pamm.202200074 221 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> @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} } 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>. 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>. A. Hamdoun, R. Mahnken, PAMM 22 (2023). 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> 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>. 542822024-05-14T09:06:38Z2024-05-14T09:15:38Z