In this paper, the authors describe a non-linear constitutive model adequate to the simulation of high temperature processes at large deformations. These constitutive equations are associated to a set of internal variables that account for phenomenological processes such as strain-hardening, material restoration and temperature history effects. Material parameters, necessary for the definition of the constitutive model, were obtained performing experimental tests. The model was implemented in a finite element code and tested with 3D tensile and shear tests on aluminium alloy specimens. In order to evaluate the performance of the numerical algorithms, the tests were done at different temperatures, ranging from room temperature to 580K. Uniaxial and simple shear stress-strain curves were obtained for a AA1050-O aluminium alloy sheet sample at different temperatures. The experimental tests were performed at low strain-rates and with parallel loading to the rolling direction. Numerical results are compared with experimental results and are in good agreement with the latter. Real material behaviour is fairly well characterized and duplicates the experimental results obtained with different solicitations and at different temperatures.