Continuum Dislocation Dynamics (CDD) theory
Nina Gunkelmann, Mehran Monavari, Stefan Sandfeld, Dominik Steinberger, Ronghai Wu, Michael Zaiser
This project investigates dynamic systems of interacting dislocations represented by density-like tensorial quantities in the framework of a continuous field theory (CDD). Our group is concerned with fundamental questions and theory development as well as with applications, e.g., to size-effects in micro-samples or to dislocation pattern formation, where we recently could identify the fundamental mechanism that is responsible also for the formation of cell structures or persistent slip bands during cyclic deformation.
This group is part of the DFG Research Group (“Forschergruppe”) FOR 1650 ( www.for1650.kit.edu) and the European M.ERA-NET project FASS (Fatigue Simulation near Surfaces).
Selected publications:
- M. Monavari, S. Sandfeld, M. Zaiser, Continuum Representation of Systems of Dislocation Lines: A General Method for Deriving Closed-Form Evolution Equations, http://arxiv.org/abs/1509.05617
- M. Zaiser, Local density approximation for the energy functional of three-dimensional dislocation systems, Phys. Rev. B 92, 2015. Preprint
- S. Sandfeld and M. Zaiser, Pattern formation in a minimal model of continuum dislocation plasticity, Model. Simul. Mater. Sci. Eng. 23, 2015.
- S. Sandfeld, V. Verbeke, B. Devincre, Orientation-dependent Pattern Formation in a 1.5D Continuum Model of Curved Dislocations, Mater Res Soc Symp Proc 1755, 2015.
- T. Hochrainer, S. Sandfeld, M. Zaiser, P. Gumbsch, Continuum dislocation dynamics: Towards a physical theory of crystal plasticity, J. Mech. Phys. Solids 63, 2014.
- S. Sandfeld, E. Thawinan, C. Wieners, A link between microstructure evolution and macroscopic response in elasto-plasticity: formulation and numerical approximation of the higher-dimensional Continuum Dislocation Dynamics theory, Int. J. Plasti., 2015. Preprint
- M. Monavari, M. Zaiser, S. Sandfeld, Comparison of closure approximations for continuous dislocation dynamics, Mater Res Soc Symp Proc 1651, 2014.
- S. Sandfeld, M. Monavari, M. Zaiser, From systems of discrete dislocations to a continuous field description: Stresses and averaging aspects, Modell. Simul. Mater. Sci. Eng. 21, 2013.