Dislocation patterns and the similitude principle: a 3D-DD simulations investigation

During plastic flow of crystalline solids, dislocation microstructures self-organize in the form of patterns, with a wavelength that is inversely proportional to stress. After decades of investigations, the exact influence of such dislocation patterns with different structures depending on the loading condition, is still under discussion. We show that dislocation patterns verifying the principle of similitude are reproduced from 3D Dislocation Dynamics simulations on a wide range of dislocation density. The simulated patterns are formed in periodic Cu volumes representative of large single crystals deformed in multi-slip. The influences of two specific properties of dislocations, i.e. collinear annihilation and cross-slip, are discussed. This new insight into the collective properties of dislocations has important implications regarding models of crystal plasticity.