research interests
Mathieu Renouf's HomePage back home


Numerical Tribology, Contact algorithms, Discrete Element Method, Granular flow, Virtual Reality

Numerical Tribology 

I joined the TMI group of the LaMCoS (a CNRS/INSA-Lyon joined unit) in October 2005, for associate researcher permanent position (CR CNRS). Multi-scale and multi-physics problems as friction and wear are the main topics of my research project. Both phenomena are investigated at a local scale, taking into account heterogeneous and discontinuous features of the contact interface.

Discrete Element Methods (DEM) are used to simulated the rheology of the contact interface. Method based on explicit or explicit time integration scheme and based on explicit or implicit treatment of contact can be used but the Non Smooth Contact Dynamics framework developped by J.-J. Moreau (1988) and M. Jean (1999) stays the core of my work.

Contact laws as well as multiphysic models are developped to represented with accuracy the interface and to understand the correlation between wear and friction. Applications involved are wheel-rail contact, brake shoes or prothesis.

DEM and Contact 

Since my Ph.D. thesis, I am involved in the development of the OpenSource code LMGC90 created by F. Dubois and M. Jean. The code is a Fortran90 code with a Oriented Object structure. Its main objective is the simulation of multi-contact systems such as granular material. Simulated objects can be considered rigid or deformable. Numerous contact laws are implemented allowing the simulation of material with different behaviour. See the webpage of the code for more details.

Virtual Reality

Since my post-doctoral position (from October 2004 to September 2005), I am interested by real time simulation. My post-doc was performed between SIAMES and BIPOP project from the INRIA (The French National Institute for Research in Computer Science and Control). The aim was to focus on the respect of the real-time constraint in the simulation of rigid multibody systems. For the description of local interactions, contact and friction are described by Non Smooth laws based on the framework of J. J. Moreau and M. Jean.
A C++ Mechanical library called ConFeTiS have been developed and embedded in OpenMASK a Virtual Reality Platform developed by the SIAMES project and takes advantages of the Numerics library of the Siconos project. This work have been performed with Vincent Acary (BIPOP) and Georges Dumont (SIAMES). Many results have been obtained with ConFeTiS, underlining the possibility of using robust mechanical method in virtual reality (see publication section for references). Different works around ConFeTiS are performed in the IRISA as well as in the INRIA Rhône-Alpes: interaction with the SiCoNoS project and interaction with Haptic interface.

Granular flows

I am also interested by Numerical Granular Media Research, especially in the rheology of the 2D and 3D surface flow. On this topic, I collaborate with Daniel Bonamy, researcher in the DRECAM group of the CEA Saclay. Description of the rheology of surface flow is the center of our collaboration. Simulations are performed with the LMGC90 open source code dedicated to the simulation of dynamical systems.

In collabration with Pr. Pierre Alart and Frédéric Dubois, we are interested by the simulation of Sandbox to study tectonic displacement and more generally to the simulation of granular material.