Materials & Design (Jul 2024)
Automatic and time-resolved determination of fracture characteristics from in situ experiments
Abstract
The characterization of materials in ever smaller dimensions is crucial for the growing demand for miniaturized devices. Hence, in situ fracture experiments are frequently performed at the micron to sub-micron scale. To evaluate fracture process of these experiments, knowledge of the crack length or the crack tip opening displacement is required. Acquired in situ frames provide a direct measurement of the crack length, crack tip opening displacement and -angle. An algorithm was developed to extract these parameters from the in situ frame sequences automatically. To verify the performance of the algorithm, fracture characteristics were measured manually for several frames of the available in situ experiments. The fracture behavior of these samples ranged from brittle over semi-brittle to ductile. The comparison between algorithmic results and manual measurements demonstrated the applicability of the algorithm to different fracture behaviors. Additionally, the fracture characteristics determined by the algorithm are in accordance with the fracture toughness data reported in literature. The crack tip opening displacement measurement gives thorough insight into the plastic deformation during fracture. The automatic extraction of the fracture characteristics allows a more detailed analysis of small-scale fracture processes and enables a reproducible, continuous evaluation of the fracture characteristics of all frames.