In spite of the huge amount of studies carried out and the many advancements achieved in the last decades in the field of dynamic crack propagation, some aspects still lack of a comprehensive interpretation, such as, for instance, the strengthening and toughening mechanisms, and the phenomenon of crack branching.
In this context, the contribution of the present project consists in the development of numerical and analytical approaches that are robust and devoid of the flaws typical of other methodologies, like the mesh dependency for the cohesive method and the difficulty to manage crack branching and coalescence for the X-FEM.
Such a goal will be pursued by following two complementary strategies: on the one hand, a numerical approach based on the Phase Field model will be developed for a more detailed study of fragmentation of materials subjected to high strain rates. A special interest is in the coupling of PF with the cohesive method in order to get the most advantages in modelling composite materials. On the other hand, the Finite Fracture Mechanics will be extended to dynamics in order to provide a useful tool for preliminary sizing of materials and structures, limiting the use of computationally expensive approaches to the final stage in the structural design, while preserving a physical insight into the fracture mechanics problem due to semi-analytical relations.
Besides contributing to answer to fundamental questions, this project is oriented to develop tools for practical applications in the field of civil engineering and manufacturing industry, where there is the need to optimize material microstructure and products’ shape in order to improve their performance in the dynamic regime. A special emphasis will be put on the additive manufacturing technology, since it makes possible to create very complex microstructured materials showing unprecedented behaviors in the dynamic regime.