|| The French-German Research Institute of Saint-Louis (ISL) situated in the border triangle of Germany, France and Switzerland is an internationally renowned research institute belonging to a global industrial and economic network. The spectrum of our core activities comprises a variety of topics: aerodynamics, energetic and advanced materials, lasers
and electromagnetic technologies, protection, security and situational awareness. Our activities are related to both basic and applied research.
Current needs in the design and optimization of complex ballisticprotection structures lead to the development of more and moreaccurate numerical modeling of high-velocity impacts. The aim of developing such a tool is to be able to predict the protectionperformance of structures with few experiments. Putting purelynumerical considerations aside, the most important issue to obtain a reliable simulation is to focus on the material behavior modeling(deformation and failure) under very high strain rates and complexstress states. An accurate description of both the projectile andtarget material behaviors is essential to get an appropriate descriptionof the protection mechanisms. Many efforts have been maderegarding the knowledge of the target behavior but there is a lackof characterisation and modeling of the projectile response whenimpacting the target.
The main challenge related to high-velocity projectiles impactingprotective structures is the sensitivity of the mechanical and failurebehavior of the material towards the stress state. Indeed, accordingto the projectile shape and the evolution of the penetration mechanismswithin the thickness of the target, the stress state can bemodified. The proposed project will focus on the study of the mechanicaland failure behavior of materials composing small-caliberprojectiles under conditions (temperature, strain rate) representativeof a ballistic impact. The studied materials will come from smallcaliber projectiles and more precisely, the core and jacket componentswill be considered. Characterising these parts in their smalloriginal shape is quite challenging and necessitates the developmentof new experimental techniques.
To reach the above-mentioned objectives, the PhD thesis will dealwith the following points:
1) Literature review focusing on the modelling of the dynamicmechanical behavior of the materials composing the studiedprojectiles and on the materials used in related body armors,
2) Mechanical characterisation of the materials with the developmentof dedicated experimental techniques,
3) Modeling of the behavior and failure of the materials, and selectionof suited numerical methods,
4) Numerical simulation of the impact of a projectile on a bodyarmor, study of the influence of the parameters (geometry, velocity,etc.) on the mechanisms involved during the penetration,
5) Validation of the material models with ballistic tests carried outat ISL.
– Strong knowledge in mechanics, metallurgy, finite elements, numerical simulation,
– Master 2 or Engineer degree validated in Mechanics or Material sciences,
– Organisational skills, ability to work effectively as a part of a team, communication skills,
– Perfect knowledge of English,
– Strong writing skills and an ability to speak in public.