The following master’s thesis was written during a period of foreign mobility, with a duration of 5 months, which was spent at Egis, a French group leader in the engineering sector. In particular, the internship was carried out in the Egis Industries (nuclear department of EGIS group), within the EAS (Egis Advanced Solutions) team. The internship aimed at validating GLRC_HEGIS nonlinear constitutive model developed by Miquel Huguet Aguilera for the software Code_Aster, by means of a several simulations aimed at reproducing the behaviour of real case studies. This constitutive law is able to reproduce the main nonlinear phenomena that characterise the behaviour of RC (reinforced concrete) elements: concrete damage, concrete cracking, bond-slip stress and yielding of steel reinforcement bars.