2. Modeling and simulating scale effects

The simulation of scale effects in crystalline plasticity poses problems specific to the continuous mechanics approach. Indeed, we note that, if we express equation (37) of the article with the variable ρb ² , the coefficients no longer have the dimension of a length, so that this law introduces no real characteristic length into the modeling and is therefore unable to account for experimentally observed scale effects (grain size or dislocation cell effects). Similarly, the multi- and polycrystal calculations presented in the graph 1