Berlin 2008 – wissenschaftliches Programm
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SYMS: Symposium Modern developments in multiphysics materials simulations
SYMS 3: Modern developments in multiphysics materials simulations III
SYMS 3.6: Vortrag
Freitag, 29. Februar 2008, 11:30–11:45, A 053
Numerical Implementation of a 3D-Continuum Theory of Dislocations — •Stefan Sandfeld1,3, Thomas Hochrainer1,2, Peter Gumbsch1,2, and Michael Zaiser3 — 1University Karlsruhe, IZBS, Karlsruhe, Germany — 2Fraunhofer IWM, Freiburg, Germany — 3University Edinburgh, U.K.
The growing demand for physically motivated continuum theories of plasticity led to an increased effort on continuum descriptions based on dislocations. For simplified systems of straight edge dislocations in a single slip configuration a 2-dim. theory is available (Groma 2003).
However, all attempts to transfer this method to 3-dim. systems of curved dislocations failed due to the lack of a dislocation density measure being able to reflect all dislocations as line like objects. The reason is that the Kroner tensor, as a measure for geometrically necessary dislocations (GND), comprises only a fraction of all dislocations, while the scalar density of statistically stored dislocations (SSD) contains no directional information.
This deficiency can be remedied by a recently introduced continuum theory of dislocations (Hochrainer 2006), which utilizes a generalized definition of the dislocation density tensor. Within this theory the differentiation between GND and SSD becomes dispensable. We explore this theory by a numerical implementation for the 2-dim. case of a single glide system. The effect of dislocation pile-ups at impenetrable boundaries is studied and compared to alternative approaches (e.g. Sedlacek 2003). We will show, that our method can treat arbitrary distributions of dislocation loops insinde the plastic slip channel.