Nowadays, pre-cracked Small Punch Tests (P-SPT) are used in those cases where there is not enough material for conducting conventional tests. In this paper, P-SPT has been used to determine the fracture properties of the 15.5PH steel, using the micromechanical model, developed by Gurson-Tvergaard-Needleman (GTN). The effect of variation of damage parameters on the numerical simulation has been analyzed. This numerical simulation is based on the sequential adjustment of the experimental load-displacement curves obtained from P-SPT. Interrupted test have been also developed in order to know the cracking process during loading and the damage evolution until fracture.
