Viscoplastic flow rule for dislocation-mediated plasticity from systematic coarse-graining
| Autor: | M Marleen Kooiman, Markus Hütter, Mgd Marc Geers |
|---|---|
| Přispěvatelé: | Processing and Performance, Mechanics of Materials, Group Geers |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Dislocations 02 engineering and technology Slip (materials science) Plasticity 01 natural sciences Crystal plasticity Condensed Matter::Materials Science 0103 physical sciences constitutive behavior 010306 general physics crystal plasticity Mechanical load Viscoplasticity Mechanical Engineering dynamics 021001 nanoscience & nanotechnology Condensed Matter Physics Classical mechanics Mechanics of Materials coarse graining Exponent Granularity Dislocation 0210 nano-technology Dislocations dynamics crystal plasticity constitutive behavior coarse graining |
| Zdroj: | Journal of the Mechanics and Physics of Solids, 90, 77-90. Elsevier |
| ISSN: | 0022-5096 |
| Popis: | The plastic response of metals is determined by the collective, coarse-grained dynamics of dislocations, rather than by the dynamics of individual dislocations. The evolution equations at both levels are quite different, for example considering their dependence on the applied mechanical load. On the one hand, the relation between the configurational force and dislocation velocity for individual dislocations is linear. On the other hand, in phenomenological crystal plasticity models, the relation between load and plastic slip is highly non-linear and often taken of power-law form. In this work, it is shown that this difference is justified and a consequence of emergent effects. Previously, an expression for the macroscopic dislocation flux was derived by systematic coarse graining ( Kooiman et al., 2015 ). This expression has been evaluated numerically in this paper. The resulting relation between dislocation flux and applied mechanical load is found to be of power-law form with an exponent 3.7, while the underlying Discrete Dislocation Dynamics has a linear flux–load relation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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