19.12.2017

Mesoscopic simulation techniques in material physics

1. Introduction

  • Survey on simulation techniques at the “mesoscopic” length scale
  • Principle problems in modelling small scale mechanical behaviour: discrete models vs. continuum mechanics

2. Theory of dislocations

  • Stress and displacement fields of dislocations
  • Line energy
  • Dislocation reactions
  • Dynamics of dislocations

3. Discrete dislocation dynamics in three dimensions

  • Possibilities of solving the boundary value problem (image forces, etc.)
  • Super position principle of Van der Giessen, Needleman, et al.
  • Equations of motion
  • Dislocation cross-slip and climb
  • Initial dislocation structures (Frank-Read sources, relaxed structures)
  • Grain and phase boundaries
  • Selected examples: micro compression/tension tests, micro bending tests, etc.
  • Comparison with other simulation techniques: advantages and disadvantages

4. Phase field models

  • Introduction in the phase field kinetic
  • Classical applications: Solidification and growth processes
  • Phase field model for dislocation motion
  • Multi phase field model for the description of crystallographic slip
  • Implementation of dislocation reactions
  • Examples of application of phase field models in dislocation dynamics

5. Continuum mechanics approaches

  • The dislocation density tensor
  • Strain gradient plasticity theories
  • Higher order continuum mechanics models

Vortragende/r: 
C. Motz

MUonline: 
Link