Applying the grid method and infrared thermography to investigate plastic deformation in aluminium multicrystal

Two different full-field measurement techniques were used in this study to investigate the mechanical response of an aluminium multicrystal specimen subjected to a tensile test. The experimental setups corresponding to each of the two techniques are first described. Strain fields were obtained with the grid method, to which a recent image treatment procedure was applied. This procedure leads to a high spatial resolution in strain and provides an accurate description of the plasticity that occurs in grains. Heat sources were derived from temperature maps captured with an infrared camera. Some typical strain maps are shown and significant heterogeneities clearly appear. These strain maps are also compared with their numerical counterparts, obtained using a finite element package suitable for crystal plasticity. The calculation of the heat source distributions from the raw temperature maps is then addressed. The strain, displacement and heat source maps were then processed together to estimate the fraction of anelastic power converted into dissipated power. This quantity was determined over the whole gauge section of the specimen and also for three individual grains.