Three-dimensional dislocation dynamics simulation of the influence of sample size on the stress–strain behavior of fcc single-crystalline pillars

The size-dependent flow stress in uniformly loaded pillars has been modeled using a discrete dislocation dynamics tool. Starting from Frank-Read sources of given length and random orientation, the simulated flow stress at 0.15% plastic strain shows a clear size effect, similar to experimental findings for larger strains. The scattering of the simulated stress–strain curves decreases with increasing sample size, which reflects that plasticity of small scale samples is very sensitive to the underlying dislocation microstructure.