Determinação da curva tensão-deformação com o auxílio da Correlação de Imagens Digitais (DIC)

Abstract

The tensile test is an important engineering tool because with it is possible to determine important information about the mechanical properties of the material. Digital Image Correlation emerges as the method that combines with conventional methods because it has the best aspects of these methods and facilitate the analysis. The method is to film a traction test with standardized samples that are properly painted with a random pattern so that the method can work. This study seeks to test the method of Digital Image Correlation to construct the stress-strain curve and the true stress-strain curve. The method consists in filming a traction test with standardized specimens and duly painted with a random pattern for the method to work. Filming is analyzed and translated by the GOM Correlate software in a strain field and the stress-strain curve is constructed using this strain data in conjunction with the stress data given by the tensile test machine. The use of this method was relatively satisfactory to construct the conventional and true tensile-strain curve much more cheaply, so that this method was used to determine important mechanical properties in the plastic region of the materials, such as true deformation and corrected tension in the post-stiffness region, so that these properties can be used in the mechanical conformation of the metals for example, as input data from simulation programs in the mechanical conformation of the metals. Acquiring quality images during the trial is critical to the success of this method. In the present work the difficulties faced in this stage are also reported, so that they can serve as a warning for future work of the difficulties encountered in the practical application of the method.