Continuum representation of systems of dislocation lines: A general method for deriving closed-form evolution equations

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Monavari M, Sandfeld S, Zaiser M
Zeitschrift: Journal of the Mechanics and Physics of Solids
Verlag: Elsevier
Jahr der Veröffentlichung: 2016
Band: 95
Seitenbereich: 575-601
ISSN: 0022-5096


Abstract


Plasticity is governed by the evolution of, in general anisotropic, systems of dislocations. We seek to faithfully represent this evolution in terms of density-like variables which average over the discrete dislocation microstructure. Starting from T. Hochrainer's continuum theory of dislocations (CDD) (Hochrainer, 2015), we introduce a methodology based on the ‘Maximum Information Entropy Principle’ (MIEP) for deriving closed-form evolution equations for dislocation density measures of different order. These equations provide an optimum representation of the kinematic properties of systems of curved and connected dislocation lines with the information contained in a given set of density measures. The performance of the derived equations is benchmarked against other models proposed in the literature, using discrete dislocation dynamics simulations as a reference. As a benchmark problem we study dislocations moving in a highly heterogeneous, persistent-slip-band like geometry. We demonstrate that excellent agreement with discrete simulations can be obtained in terms of a very small number of averaged dislocation fields containing information about the edge and screw components of the total and excess (geometrically necessary) dislocation densities. From these the full dislocation orientation distribution which emerges as dislocations move through a channel-wall structure can be faithfully reconstructed.



FAU-Autoren / FAU-Herausgeber

Monavari, Mehran
Lehrstuhl für Werkstoffsimulation
Sandfeld, Stefan Dr.
Lehrstuhl für Werkstoffsimulation
Zaiser, Michael Prof. Dr.
Lehrstuhl für Werkstoffsimulation


Zitierweisen

APA:
Monavari, M., Sandfeld, S., & Zaiser, M. (2016). Continuum representation of systems of dislocation lines: A general method for deriving closed-form evolution equations. Journal of the Mechanics and Physics of Solids, 95, 575-601. https://dx.doi.org/10.1016/j.jmps.2016.05.009

MLA:
Monavari, Mehran, Stefan Sandfeld, and Michael Zaiser. "Continuum representation of systems of dislocation lines: A general method for deriving closed-form evolution equations." Journal of the Mechanics and Physics of Solids 95 (2016): 575-601.

BibTeX: 

Zuletzt aktualisiert 2018-15-11 um 13:50