  An anisotropic damage model is employed in order to simulate the fracture
pattern of Bohus granite under quasi-static spherical indentation loading. The
chosen damage description is added to the previously employed Drucker-Prager
plasticity model with variable dilation angle. The resulting constitutive model
is implemented to simulate the behavior of Bohus granite under indentation up
to the load capacity of the material. The initial fragmentation, corresponding
to the first small load-drop in the force-penetration curve, is likely due to
the high radial tensile stress state at or close to the contact boundary. Both
predicted fracture pattern and force-penetration results from the numerical
simulation are compared to experimental data and a good agreement is found. The
variability in tensile strength of the material is included in the chosen
damage model by taking advantage of Weibull statistics. In this work, it is
suggested that indentation test results by themselves may be used to calibrate
the statistical distribution of tensile strength at small size scales such as
in indentation applications.
