Integración de correlación digital de imágenes y termoelasticidad para el cálculo de los factores de intensidad de tensiones

Abstract

2D Digital Image Correlation (2D DIC) is a widely used and established full-field non-contact technique. It is presented as a simple and robust technique to obtain maps of displacements and stresses from the deformed surface of a structure. On the other hand, differential thermography and, in particular, Thermoelastic Stress Analysis (TSA), has experienced an important evolution with the technological development of infrared array detectors. The applicability and potential of both techniques has been reported for the analysis of crack tip plasticity during fatigue crack growth. However, little research has been done on the combination and interpretation of both techniques for this purpose. In this paper, both techniques have been employed to quantify the size of plastic zone at the crack tip. In the case of DIC, it is done by employing a yielding criterion in combination with the measured strains, while with TSA the phase map for both, the first and the second harmonic are employed during for the case of cyclic loading under constant amplitude. Finally, a relation between the phase of the thermoelastic signal and the crack closure phenomenon has been discussed