Finite element analysis of the indentation test on rocks with   microstructure
  Strength parameters of rocks are currently determined from indentation tests. In this paper, a finite element analysis of this test is presented and scale effect is studied. The rock is modelled as an elasto-plastic medium with Cosserat microstructure and consequently possesses an internal length. The response of the indentation curve is studied for various values of the size of the indentor as compared to the internal length of the rock in order to assess the scale effect. 
Jean Sulem (ENPC-CERMES), Miguel Cerrolaza