ABSTRACT
The inelastic behavior of Bohus granite is studied based on experimental and numerical results. A number of quasi-static indentation tests are carried out. Several small and large load-drops are noticed in the force-penetration responses during those tests. These load drops are probably due to conical, Hertzian cracks initiated at the surface of the rock specimens. Each of these load drops are corresponding to a material removal event in the region with positive hydrostatic stress (negative pressure) state at the rock surface enclosing the growing contact boundary. Moreover, the P-h response after the first large load-drop is highly affected by cracking and fragmentation in this material. Therefore in order to predict the load-drop force levels and the response after the first large load-drop, a pressure-dependent damage criteria seems required.
