2021-04172 - PhD Position F/M Non-smooth modeling of the interaction between granular flow and 3d obstacles. [PHD INRIA/INRAE]

Contract type : Fixed-term contract

Level of qualifications required : Graduate degree or equivalent

Fonction : PhD Position

About the research centre or Inria department

Grenoble Rhône-Alpes Research Center groups together a few less than 650 people in 35 research teams and 8 research support departments.

Staff is localized on 5 campuses in Grenoble and Lyon, in close collaboration with labs, research and higher education institutions in Grenoble and Lyon, but also with the economic players in these areas.

Present in the fields of software, high-performance computing, Internet of things, image and data, but also simulation in oceanography and biology, it participates at the best level of international scientific achievements and collaborations in both Europe and the rest of the world.

Context


TRIPOP (Inria Grenoble Rhône-Alpes ; Laboratoire Jean Kuntzmann) team is mainly concerned by the modeling, the simulation and the control of nonsmooth dynamical systems. In mechanics, the main instances of nonsmooth dynamical systems are multibody systems with Signorini's unilateral contact, set-valued (Coulomb-like) friction and impacts, or in continuum mechanics, ideal plasticity, fracture or damage. The members of the team have a long experience of nonsmooth dynamics modeling together with the development of simulation software.

INRAE's ETNA Research Unit is recognized for many years at the international level for its work on snow and on protection structures against natural hazards. Its skills relate to physical and digital modeling, laboratory and on-site experimentation, and instrumentation in difficult alpine contexts.

Assignment

In the context of global changes, gravitational natural hazards, such as landslides, rock and snow avalanches and debris flows, are increasingly threatening people and infrastructures in mountainous regions. For most of these processes, the hazard assessment requires quantifying the initiation, propagation and stopping phases, including the impact onto structures.
The mitigation measures against these gravitational hazards are mainly based on the design of protection structures that reduce the propagation of the flow by means of energy dissipation during the interaction between the flow and the structure.
The scientific challenge for the assessment of the interaction between gravitational mass flows and structures is in many cases related to the understanding of the interplay between the hydrodynamic flow properties and the discrete nature of the material involved (dry grains, cohesive grains, mixture of grains and surrounding fluid).
The study of the interaction between granular flows and obstacles is a complex physical problem that is today a booming research area increasingly addressed by using both numerical and experimental approaches.
Most of research work focuses on simplified configurations involving 2D dry granular flow interacting with rigid wall-like obstacles. More recently, several researches started to investigate the effects of material properties, involving cohesive materials, for example, and of structure geometry and deformability.
This increased complexity of the processes is challenging in terms of numerical modelling : efficient and relevant modelling techniques involving complex numerical methods have to be developed.

Main activities

The objective of the PhD is to use non smooth numerical modelling to analyse the physical processes involved in the interaction between complex granular flows interacting with 3D deformable structures.
The main tasks of this research work are to :

  •  develop 3D numerical simulations involving complex granular materials (cohesive, in particular) interacting with deformable structures
  • optimize the numerical model to allow extensive numerical simulations for complex 3D problems on high performance computing architecture
  • perform detailed physical analyses of the interaction not only for simplified configurations but also for complex 3D ones, with a focus on the interplay between the hydrodynamic-like patterns formed (jumps, dead zones, etc.) and the discrete nature of the flowing material and its effect on the resulting impact force

Name of the co-supervisors :
Vincent Acary (HdR, INRIA-Tripop) vincent.acary@inria.fr
Thierry Faug (HdR, INRAE-ETNA) thierry.faug@inrae.fr
Franck Bourrier (HdR, INRAE-ETNA and INRIA-Tripop) franck.bourrier@inrae.fr

Skills


The PhD candidate should have competences in mechanics and numerical modeling. A strong theoretical background in fluid and solid mechanics is mandatory. Furthermore, the applicant must show a strong interest for software development in computational Mechanics. He also has to be motivated by applied research in collaboration with researchers from different disciplines. A good level of English and subsequent writing capacities are also requested.

Benefits package

  • 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 (90 days / year) 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

Remuneration

1st and 2nd year: 1 982 euros gross salary /month

3rd year: 2 085 euros gross salary / month