Discrete dislocation simulations of the plasticity of micro-pillars under uniaxial loading

Recent experiments have shown an unexpected strong size effect in uniaxial compression tests of metallic micro-pillars, such as the flow stress increases with decreasing pillar diameter. In our work, we apply three-dimensional discrete dislocation dynamics (DDD) to simulate these experiments on a mesoscopic level. Although we simulate systems with a constant source size and density, the simulations show a size effect related to size-dependent differences in details of the dislocation behavior in excellent agreement with the experiments.