Per: Daniel Scandiuzzi Valença de Castro (Universidade federal do RIO de Janeiro), Rafael de azevedo cidade (Universidade Federal do rio de janeiro), Enrique Mariano Castrodeza (Politecnico di milano)
Abstract:
The work proposes the use of data provided by digital image correlation for the calculation of the fracture toughness of a laminated composite subjected to dynamic compression. Tests were performed on a Hopkinson pressure bar using DENC (double edge notched) geometry specimens painted with a speckles pattern. The specimens were recorded during the test by a high-resolution temporal camera. Based on captured images and speckles’ distribution, a model was proposed to determine the most appropriate analysis parameters. From the displacement and deformation fields provided by the digital image correlation, the toughness was estimated using the Integral-J method, considering the inertial effects. It was demonstrated that the integral-J method integrating in area inside the contour has good applicability and is less sensitive to method parameters, presenting a maximum discrepancy of 14% between the results for the same sample. However, for the results of different samples of the same class, no satisfactory consistency was observed, but it was found, at a certain level, agreement with the values found by Kuhn et al [1] for the same material using another methodology. In parallel, it was concluded the inertial effect is negligible, indicating a state of dynamic equilibrium in which quasi-static approaches can be applied.