Résumé
Thermal field measurements are interesting tools to study thermomechanical couplings often associated with deformation of materials. Intensity and spatio-temporal distribution of the temperature variations are depending on the material behaviour (elasticity, plasticity, viscosity, damage, phase transformation,...) but also on the different characteristics of the thermal problem (geometry, thermal properties, boundary conditions, ...). Previous work [1] has shown the interest to study the local heat sources, causes of the temperature variations. Different methods have been proposed to get such heat source fields [2]. The method used in this work to estimate heat sources is based on approximations of derivative operators involved in the heat diffusion equation [1]. It was applied to study Lüders bands and necking in steels, PLC bands in AlMg alloys, plasticity in Al olygocrystals and stress induced phase transformation in Nickel-Titanium (NiTi) shape memory alloys [3].