Appel à Candidature Thèse : Analysis and numerical modeling of dynamic fragmentation processes in brittle materials over a wide strain rate range

The analysis of multiple fragmentation processes in brittle materials at high strain-rates has been a key area of the RV team for about ten years. Original experimental configurations have been developed to experimentally characterize the dynamic strength and cracking density as a function of the strain rate in different brittle materials. However, many shortcomings persist in terms of range of loading-rates, location of the spalling area and quantification of the cracking density generated at high loading rates. In addition, discrete and continuous modeling approaches, although based on data of microtomography analysis, struggle to explain the cracking densities observed experimentally. This project proposes to develop new experimental configurations to refine the characterization of dynamic fragmentation processes over a much wider range of strain rates. Moreover, the development of numerical simulations based on phase-field method will allow taking into account the energy of cracking of the material in the form of a cohesive law making it possible to better describe the phenomena of propagation of cracks at work in the processes of dynamic fragmentation.