Post-Doctoral Research Visit F/M Identification and modelling of fibre aggregates

The Centre Inria de l’Université de Grenoble groups together almost 450 people in 26 research teams and 9 research support departments.

Staff is present on three campuses in Grenoble, in close collaboration with other research and higher education institutions (Université Grenoble Alpes, CNRS, CEA, INRAE, …), but also with key economic players in the area.

The Centre Inria de l’Université Grenoble Alpes is active in the fields of high-performance computing, verification and embedded systems, modeling of the environment at multiple levels, and data science and artificial intelligence. The center is a top-level scientific institute with an extensive network of international collaborations in Europe and the rest of the world.

Context: Under some specific stress conditions, random fibrous assemblies may spontaneously yield aggregates of finite size. In nature and industry, examples span from amyloid fibres and spherical packings of marino algae to dust bunnies, hair wisps and glass fibre flakes. In addition to the spontaneous emerging of a number of ’clumps’ or ’packets’, each one of this clumps exhibits some strong resistance against stretching or shearing, which can be viewed as the emerging of some cohesive behaviour at the macroscopic scale, although no cohesive contact is involved at the micro scale. This outstanding property is leveraged by birds for making nests, and starts being investigated by scientists and architects for building lightweight self-supporting structures at large scales. Besides the scarce physical studies and little understanding of all these complex phenomena, there are still very few attempts to reproduce them with simulation so far.

Objectives: In this project our goal is to explore, understand and model the clumping behaviour that seems to spontaneously emerge in random assemblies of naturally curved fibres interacting solely through contact and friction. To that aim we shall leverage lab experiments and numerical tools (built in our team) to explore different scenarios, in 2D and in 3D, where clumping can be identified and characterised. In a second step, relying on these findings, a theoretical model for clumping will be investigated.

This work will take advantage of the numerical Kirchhoff models for rods, contact detection, and frictional contact solvers developed by the Elan team, and additionally, we expect for this study to have an important experimental component to conceive novel setups and collect data to compare with simulations.

Required Skills: Candidates must hold a PhD in any field among physics / mechanical engineering / applied mathematics / computer science, and have a proven research track record, demonstrated by publications in peer-reviewed journals in one or more of the above areas. A good background in (theoretical or experimental) physics and solid mechanics is expected. Additional skills in dynamical systems, numerical analysis, optimisation, and/or algorithmics and programmation (Python, Mathematica, or C/C++) are a plus. Curiosity and taste for understanding nonlinear physical problems using combined theoretical, experimental and numerical tools are appreciated. 

• Subsidized meals
• Partial reimbursement of public transport costs
• Leave: 7 weeks of annual leave + 10 extra days off due to RTT (statutory reduction in working hours) + possibility of exceptional leave (sick children, moving home, etc.)
• Possibility of teleworking and flexible organization of working hours
• Professional equipment available (videoconferencing, loan of computer equipment, etc.)
• Social, cultural and sports events and activities
• Access to vocational training
• Social security coverage under conditions

2788 € gross salary / month