Details
| Original language | English |
|---|---|
| Title of host publication | ECCOMAS 2012 |
| Subtitle of host publication | European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers |
| Pages | 6213-6228 |
| Number of pages | 16 |
| Publication status | Published - 1 Dec 2012 |
| Event | 6th European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2012 - Vienna, Austria Duration: 10 Sept 2012 → 14 Sept 2012 |
Publication series
| Name | ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers |
|---|
Abstract
It is well known that metals behave anisotropically on their microstructure due to their crystalline nature. FE-simulations in the metal forming field however sometimes lack the right macroscopic anisotropies as their type can be unspecific. In order to find a suitable effective elastoplastic material model, a finite crystal plasticity model is used to model the behaviour of polycrystalline materials in representative volume elements (RVEs) representing the microstructure, taking into account the plastic anisotropy due to dislocations occurring within considered slip systems. A multiplicative decomposition of the deformation gradient into elastic and plastic parts is performed, as well as the split of the elastic free energy into volumetric and deviatoric parts resulting in a compact expression of the resolved SCHMID stress depending on the slip system vectors. In order to preserve the plastic incompressibility condition, the elastic deformation gradient is updated via an exponential map scheme. To further circumvent singularities stemming from the linear dependency of the slip system vectors, a viscoplastic power-law is introduced providing the evolution of the plastic slips and slip resistances. The model is validated with experimental microstructural data under deformation. Through homogenisation and optimisation techniques, effective stress-strain curves are determined and can be compared to results from real manufacturing and fabrication processes leading to an effective elastoplastic material model which is suitable for metal forming processes at finite strains.
Keywords
- Effective material model, Finite crystal plasticity, Homogenisation, Sheet bulk metal forming
ASJC Scopus subject areas
- Computer Science(all)
- Computational Theory and Mathematics
- Mathematics(all)
- Applied Mathematics
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ECCOMAS 2012: European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers. 2012. p. 6213-6228 (ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Computational homogenisation of polycrystalline elastoplastic microstructures at finite deformation
AU - Lehmann, Eva
AU - Loehnert, Stefan
AU - Wriggers, Peter
PY - 2012/12/1
Y1 - 2012/12/1
N2 - It is well known that metals behave anisotropically on their microstructure due to their crystalline nature. FE-simulations in the metal forming field however sometimes lack the right macroscopic anisotropies as their type can be unspecific. In order to find a suitable effective elastoplastic material model, a finite crystal plasticity model is used to model the behaviour of polycrystalline materials in representative volume elements (RVEs) representing the microstructure, taking into account the plastic anisotropy due to dislocations occurring within considered slip systems. A multiplicative decomposition of the deformation gradient into elastic and plastic parts is performed, as well as the split of the elastic free energy into volumetric and deviatoric parts resulting in a compact expression of the resolved SCHMID stress depending on the slip system vectors. In order to preserve the plastic incompressibility condition, the elastic deformation gradient is updated via an exponential map scheme. To further circumvent singularities stemming from the linear dependency of the slip system vectors, a viscoplastic power-law is introduced providing the evolution of the plastic slips and slip resistances. The model is validated with experimental microstructural data under deformation. Through homogenisation and optimisation techniques, effective stress-strain curves are determined and can be compared to results from real manufacturing and fabrication processes leading to an effective elastoplastic material model which is suitable for metal forming processes at finite strains.
AB - It is well known that metals behave anisotropically on their microstructure due to their crystalline nature. FE-simulations in the metal forming field however sometimes lack the right macroscopic anisotropies as their type can be unspecific. In order to find a suitable effective elastoplastic material model, a finite crystal plasticity model is used to model the behaviour of polycrystalline materials in representative volume elements (RVEs) representing the microstructure, taking into account the plastic anisotropy due to dislocations occurring within considered slip systems. A multiplicative decomposition of the deformation gradient into elastic and plastic parts is performed, as well as the split of the elastic free energy into volumetric and deviatoric parts resulting in a compact expression of the resolved SCHMID stress depending on the slip system vectors. In order to preserve the plastic incompressibility condition, the elastic deformation gradient is updated via an exponential map scheme. To further circumvent singularities stemming from the linear dependency of the slip system vectors, a viscoplastic power-law is introduced providing the evolution of the plastic slips and slip resistances. The model is validated with experimental microstructural data under deformation. Through homogenisation and optimisation techniques, effective stress-strain curves are determined and can be compared to results from real manufacturing and fabrication processes leading to an effective elastoplastic material model which is suitable for metal forming processes at finite strains.
KW - Effective material model
KW - Finite crystal plasticity
KW - Homogenisation
KW - Sheet bulk metal forming
UR - http://www.scopus.com/inward/record.url?scp=84871633856&partnerID=8YFLogxK
U2 - 10.1002/pamm.201110192
DO - 10.1002/pamm.201110192
M3 - Conference contribution
AN - SCOPUS:84871633856
SN - 9783950353709
T3 - ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers
SP - 6213
EP - 6228
BT - ECCOMAS 2012
T2 - 6th European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2012
Y2 - 10 September 2012 through 14 September 2012
ER -