Guilhem MOLLON
guilhem.mollon@insa-lyon.fr
Associate Professor
National Institute for Applied Sciences of Lyon
PhD, Civil Engineering, INSA Lyon
HDR, INSA Lyon
Guilhem MOLLON
guilhem.mollon@insa-lyon.fr
Associate Professor
National Institute for Applied Sciences of Lyon
PhD, Civil Engineering, INSA Lyon
HDR, INSA Lyon
Geomechanics and tribology are two scientific fields which are traditionnally experimental, but which are using more and more numerical simulations as tools for understanding and prediction. A large part of my scientific activity consists in developping novel numerical tools dedicated to these two disciplines.
The first code developped in this framework is a microsctructure generator used as a preprocessor for Discrete Element Modelling of the wear of frictional surfaces. The input parameters are the roughness of the surface (amplitude, frequency, anisotropy), the geometry of the grains (size, anisotropy), and the boundary conditions (périodicity, etc.).
A complete simulation code has been developped since 2015, called MELODY (Multibody ELement-free Open code for Dynamic simulations). It is based on the coupling of conventionnal Discrete Element Method (albeit with arbitrary grain shapes) and a multibody meshfree approach for highly compliant grains. It is coded in C++ and parallelized in OpenMP, and uses a matlab preprocessor. This code is now used in production on a number of scientific applications, ranging from tribology to geophysics. Future developments will be dedicated to heat production and flow, fragile failure of grains, and to a 3D extension.
Figure 1. Rough random surfaces generator.
Figure 3. Microstructures generated with different shapes and anisotropies of the grains.
Figure 5. Meshfree discretization of a circular grain.
Figure 7. Contact management: coarse detection by sweep-and-prune.
Figure 8. Contact management: fine detection by a node-to-segment approach.
Figure 9. Contact management: due to the high angularity of the grains, a symmetric approach is prefered to the more common master-and-slave framework.
Figure 2. Microstructures generated with different thicknesses and grain sizes.
Figure 4. 3D discrete modelling of the wear of a microstructured rough surface.
Figure 6. Meshfree shape functions (MLS and RPIM).
Figure 10. Stress field in a sample comprising both rigid and deformable grains, at the initial state and after shearing.