Concept
Asperity (materials science)
Publications associées (43)
Roughness Evolution Induced by Third-Body Wear
Jean-François Molinari, Antonio Joaquin Garcia Suarez, Tobias Brink
Surface roughness is a key factor when it comes to friction and wear, as well as to other physical properties. These phenomena are controlled by mechanisms acting at small scales, in which the topography of apparently flat surfaces is revealed. Roughness i ...
New York2024A story of two transitions: From adhesive to abrasive wear and from ductile to brittle regime
Jean-François Molinari, Sacha Zenon Wattel
Atomistic simulations performed with a family of model potential with tunable hardness have proven to be a great tool for advancing the understanding of wear processes at the asperity level. They have been instrumental in finding a critical length scale, w ...
2024Capsizing due to friction-induced twist in the failure of stopper knots
Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns
We investigate the failure mechanism of stopper knots, with a particular focus on the figure -8 knot as a representative example. Stopper knots are widely used in climbing, sailing, racket stringing, and sewing to maintain tension in ropes, strings, or thr ...
Elsevier2024Modeling of rough contact interfaces with trapped compressive liquid pockets
Jean-François Molinari, Guillaume Anciaux, Parissasadat Alavi, Julie Richard, Loris Rocchi
Boundary and mixed lubrication are usually used to reduce friction in sheet metal form- ing. In the boundary lubrication regime load is mainly carried by contacting asperities. Therefore, the tribological problem can be solved in the dry case using a geome ...
2023Modeling the origins of adhesive wear across scales
Friction and wear occur at every interface between solid materials.In the design of mechanical devices, it is desirable to be able to quantify and control the amount of friction and wear, as well as predict their evolution with time. ``Tribology'' is the s ...
EPFL2022Understanding the mechanisms of adhesive wear for heterogeneous materials through atomistic simulations
Jean-François Molinari, Antonio Joaquin Garcia Suarez, Sacha Zenon Wattel
When two rough surfaces slide against each other, two main behaviors can be observed at the asperity level: A ductile behavior where the asperities tend to smooth out or a brittle behavior where the asperities detach and form debris. Recently, a critical l ...
ELSEVIER2022A numerical study of the statistics of roughness parameters for fluctuating interfaces
Self-affine rough interfaces are ubiquitous in experimental systems, and display characteristic scaling properties as a signature of the nature of disorder in their supporting medium, i.e. of the statistical features of its heterogeneities. Different metho ...
2021Onset of sliding across scales: How the contact topography impacts frictional strength
Jean-François Molinari, Ramin Aghababaei, Fabian Barras
When two solids start rubbing together, frictional sliding initiates in the wake of slip fronts propagating along their surfaces in contact. This macroscopic rupture dynamics can be successfully mapped on the elastodynamics of a moving shear crack. However ...
AMER PHYSICAL SOC2021Adhesive wear regimes on rough surfaces and interaction of micro-contacts
Jean-François Molinari, Son-Jonathan Pham-Ba
We develop an analytical model of adhesive wear between two unlubricated rough surfaces, forming micro-contacts under normal load. The model is based on an energy balance and a crack initiation criteria. We apply the model to the problem of self-affine rou ...
2021Nonlocal Effects Reflect the Jamming Criticality in Frictionless Granular Flows Down Inclines
Matthieu Wyart, Hugo Robin Louis Perrin
The jamming transition is accompanied by a rich phenomenology such as hysteresis or nonlocal effects that is still not well understood. Here, we experimentally investigate a model frictionless granular layer flowing down an inclined plane as a way to disen ...
AMER PHYSICAL SOC2021