Advances on mode I fracture testing in brittle and quasi-brittle materials with x-ray tomography

Through the case study of nuclear graphite, we show how x-ray computed tomography and Digital Volume Correlation enable quantitative monitoring of plasticity development in-situ in volume during material failure. Using a specific sample test geometry particularly suited for x-ray tomography, we applied Digital Volume Correlation to extract the strain field. Application of an experimentally derived threshold is used to distinguish between elastic’s and plastic strains around the crack tip, which allow the monitoring of the extension of the fracture process zone during crack propagation. Moreover, dynamic experiments with a time resolution up to the millisecond are now feasible using a recently suggested combination of X-ray computed tomography and Digital Volume Correlation.