Publications associées à Friction and Hertzian contact in granular glass

Effect of wear particles and roughness on nanoscale friction

Jean-François Molinari, Enrico Milanese, Tobias Brink

Frictional contacts lead to the formation of a surface layer called the third body, consisting of wear particles and structures resulting from their agglomerates. Its behavior and properties at the nanoscale control the macroscopic tribological performance ...

2022

Modeling the origins of adhesive wear across scales

Son-Jonathan Pham-Ba

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 ...

EPFL2022

Understanding the mechanisms of adhesive wear for heterogeneous materials through atomistic simulations

Jean-François Molinari, Sacha Zenon Wattel, Antonio Joaquin Garcia Suarez

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 ...

2022

Adhesive 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 ...

2021

A lubricated tribocorrosion model incorporating surface roughness

Stefano Mischler, Shoufan Cao

This study presents an improvement of an existing tribocorrosion model developed for passive CoCrMo alloys. This model is based on an empirical formalism established by Duncan Dowson in his pioneering works on the relation between wear and elasto-hydrodyna ...

2021

A parameter-free mechanistic model of the adhesive wear process of rough surfaces in sliding contact

Jean-François Molinari, Lucas Henri Galilée Frérot, Tobias Brink

In order to develop predictive wear laws, relevant material parameters and their influence on the wear rate need to be identified. Despite decades of research, there is no agreement on the mathematical form of wear equations and even the simplest models, s ...

2021

Bridging scales in wear modeling with volume integral methods for elastic-plastic contact

Lucas Henri Galilée Frérot

All mechanical systems, naturally occurring or human-produced, are subjected to friction and wear at the interface of solid constituents. Large portions of energy dissipation and loss of material, in every-day life and industrial applications alike, are du ...

EPFL2020

Adhesive wear and interaction of tangentially loaded micro-contacts

Jean-François Molinari, Son-Jonathan Pham-Ba, Tobias Brink

Current engineering wear models are often based on empirical parameters rather than built upon physical considerations. Here, we look for a physical description of adhesive wear at the microscale, at which the interaction between two surfaces comes down to ...

2020

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

Surface roughness evolution in adhesive wear processes

Enrico Milanese

Geological faults movements generating earthquakes, a vehicles' tyres rolling on the pavement, and a chalk writing on a blackboard are all different examples of frictional systems. In these systems, which are everywhere around us, two separate bodies are i ...

EPFL2020

Fault Stability Across the Seismogenic Zone

François Xavier Thibault Passelègue

Across the seismogenic zone, the transition from brittle to plastic deformation corresponds to a semibrittle regime where brittle fracturing and plastic flow coexist at high strength conditions. Thorough experimental investigations on brittle-plastic trans ...

AMER GEOPHYSICAL UNION2020

Jamming with Tunable Roughness

Matthieu Wyart, Carolina Brito Carvalho dos Santos

We introduce a new model to study the effect of surface roughness on the jamming transition. By performing numerical simulations, we show that for a smooth surface, the jamming transition density and the contact number at the transition point both increase ...

AMER PHYSICAL SOC2020

The transfer of forces through rough surface contact in concrete

Max Tirassa

Aggregate interlocking is a phenomenon occurring when the opposite sides of a concrete crack slide relative to each other. Due to surface roughness, protruding material from one crack-side can engage with the opposite one and thus exchange forces. This aff ...

EPFL2020

Crack Nucleation in the Adhesive Wear of an Elastic-Plastic Half-Space

Jean-François Molinari, Guillaume Anciaux, Lucas Henri Galilée Frérot

The detachment of material in an adhesive wear process is driven by a fracture mechanism which is controlled by a critical length-scale. Previous efforts in multi-asperity wear modeling have applied this microscopic process to rough elastic contact. Howeve ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Adhesive wear mechanisms in the presence of weak interfaces: Insights from an amorphous model system

Jean-François Molinari, Tobias Brink

Engineering wear models are generally empirical and lack connections to the physical processes of debris generation at the nanoscale to microscale. Here, we thus analyze wear particle formation for sliding interfaces in dry contact with full and reduced ad ...

2019

Quantifying uncertainties in contact mechanics of rough surfaces using the multilevel Monte Carlo method

Fabio Nobile, Sebastian Krumscheid, Valentine Ginette Madeleine Rey

We quantify the effect of uncertainties on quantities of interest related to contact mechanics of rough surfaces. Specifically, we consider the problem of frictionless non adhesive normal contact between two semi infinite linear elastic solids subject to u ...

2019

A mechanistic understanding of the wear coefficient: From single to multiple asperities contact

Jean-François Molinari, Lucas Henri Galilée Frérot, Ramin Aghababaei

Sliding contact between solids leads to material detaching from their surfaces in the form of debris particles, a process known as wear. According to the well-known Archard wear model, the wear volume (i.e. the volume of detached particles) is proportional ...

2018

Asperity-Level Origins of Transition from Mild to Severe Wear

Jean-François Molinari, Ramin Aghababaei, Tobias Brink

Wear is the inevitable damage process of surfaces during sliding contact. According to the well-known Archard’s wear law, the wear volume scales with the real contact area and as a result is proportional to the load. Decades of wear experiments, however, s ...

2018

Adhesive wear mechanisms uncovered by atomistic simulations

Jean-François Molinari, Lucas Henri Galilée Frérot, Ramin Aghababaei, Enrico Milanese, Tobias Brink

In this review, we discuss our recent advances in modeling adhesive wear mechanisms using coarse-grained atomistic simulations. In particular, we present how a model pair potential reveals the transition from ductile shearing of an asperity to the formatio ...

SPRINGEROPEN2018

Modeling tribocorrosion of passive metals - A review

Stefano Mischler, Shoufan Cao

Tribocorrosion is a material degradation phenomenon resulting from interactive effects between wear and corrosion. It is commonly found in engineering applications (e.g. biomedical implants and marine equipment) which involve relative motion of contacting ...

PERGAMON-ELSEVIER SCIENCE LTD2018