Publications by Ramin Aghababaei

How roughness emerges on natural and engineered surfaces

Jean-François Molinari, Ramin Aghababaei

Roughness, defined as unevenness of material surfaces, plays an important role in determining how engineering components or natural objects interact with other bodies and their environment. The emergence of fractal roughness on natural and engineered surfa ...

SPRINGER HEIDELBERG2023

Onset of sliding across scales: How the contact topography impacts frictional strength

Jean-François Molinari, Fabian Barras, Ramin Aghababaei

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 SOC2021

Role of interfacial adhesion on minimum wear particle size and roughness evolution

Jean-François Molinari, Ramin Aghababaei, Enrico Milanese, Tobias Brink

Adhesion between two bodies is a key parameter in wear processes. At the macroscale, strong adhesive bonds are known to lead to high wear rates, as observed in clean metal-on-metal contact. Reducing the strength of the interfacial adhesion is then desirabl ...

2020

Emergence of self-affine surfaces during adhesive wear

Jean-François Molinari, Ramin Aghababaei, Enrico Milanese, Tobias Brink

Friction and wear depend critically on surface roughness and its evolution with time. An accurate control of roughness is essential to the performance and durability of virtually all engineering applications. At geological scales, roughness along tectonic ...

Nature Research2019

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

Modeling and simulation in tribology across scales: An overview

Jean-François Molinari, Guillaume Anciaux, Vladislav Yastrebov, Ramin Aghababaei, Gianluca Costagliola

2018

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

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

The role of hardness in the surface roughness evolution during adhesive wear processes

Jean-François Molinari, Ramin Aghababaei, Enrico Milanese

2017

On the debris-level origins of adhesive wear

Jean-François Molinari, Ramin Aghababaei, Derek Warner

Every contacting surface inevitably experiences wear. Predicting the exact amount of material loss due to wear relies on empirical data and cannot be obtained from any physical model. Here, we analyze and quantify wear at the most fundamental level, i.e., ...

Natl Acad Sciences2017

Critical length scale controls adhesive wear mechanisms

Jean-François Molinari, Ramin Aghababaei, Derek Warner

The adhesive wear process remains one of the least understood areas of mechanics. While it has long been established that adhesive wear is a direct result of contacting surface asperities, an agreed upon understanding of how contacting asperities lead to w ...

Springer2016

Impact of internal crystalline boundaries on lattice thermal conductivity: Importance of boundary structure and spacing

Jean-François Molinari, Guillaume Anciaux, Ramin Aghababaei

The low thermal conductivity of nano-crystalline materials is commonly explained via diffusive scattering of phonons by internal boundaries. In this study, we have quantitatively studied phononcrystalline boundaries scattering and its effect on the overall ...

AIP American Institute of Physics2014