  Coupling of nano-indentation and crystal plasticity finite element (CPFE)
simulations is widely used to quantitatively probe the small-scale mechanical
behaviour of materials. Earlier studies showed that CPFE can successfully
reproduce the load-displacement curves and surface morphology for different
crystal orientations. Here, we report the orientation dependence of residual
lattice strain patterns and dislocation structures in tungsten. For
orientations with one or more Burgers vectors close to parallel to the sample
surface, dislocation movement and residual lattice strains are confined to
long, narrow channels. CPFE is unable to reproduce this behaviour, and our
analysis reveals the responsible underlying mechanisms.
