Discrete dislocation simulation of nanoindentation: the effect of moving conditions and indenter shape

Nanoindentation is simulated by means of movement of discrete dislocations. It is shown that the nominal hardness of the material in our model is mainly influenced by the critical shear stress necessary to activate the dislocation sources, whereas the level of decrease of the hardness at small indentation depth is dependent on the lattice friction stress for the dislocation movement. In our plastic analysis the influence of a cylindrical indenter and of a wedge-shaped indenter with a rounded tip is also studied.