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Daniel Mulvihill's picture

Postdoctoral Researcher in the Mechanics & Tribology of Triboelectric Nanogenerators (University of Glasgow, UK)

The James Watt School of Engineering is looking for a postdoctoral researcher to contribute to/make a leading contribution to a large international EPSRC funded project looking at the physics and mechanics of triboelectric nanogenerators (or TENGs).  This position will focus on the mechanics and tribology of TENGs and will involve both experimental & modelling work. Of particular interest is modelling and experimental analysis aimed at understanding, predicting and optimising the contact area and charge transfer at triboelectric interfaces.

jfmolinari's picture

Journal club for December 2023 : Recent trends in modeling of asperity-level wear

Ernest Rabinowicz’s words, spoken two decades ago in his groundbreaking textbook on the friction and wear of materials [1], continue to resonate today: ’Although wear is an important topic, it has never received the attention it deserves.’ Rabinowicz’s work laid the foundation for contemporary tribology research [2]. Wear, characterized as the removal and deformation of material on a surface due to the mechanical action of another surface, carries significant consequences for the economy, sustainability, and poses health hazards through the emission of small particles. According to some estimates [1, 3], the economic impact is substantial, accounting for approximately 5% of the Gross National Product (GNP).

Despite its paramount importance, scientists and engineers often shy away from wear analysis due to the intricate nature of the underlying processes. Wear is often perceived as a ”dirty” topic, and with good reason. It manifests in various forms, each with its own intricacies, arising from complex chemical and physical processes. These processes unfold at different stages, creating a time-dependent phenomenon influenced by key parameters such as sliding velocity, ambient or local temperature, mechanical loads, and chemical reactions in the presence of foreign atoms or humidity.

The review paper by Vakis et al. [5] provides a broad perspective on the complexity of tribology problems. This complexity has led to numerous isolated studies focusing on specific wear mechanisms or processes. The proliferation of empirical wear models in engineering has resulted in an abundance of model variables and fit coefficients [6], attempting to capture the intricacies of experimental data.

Tribology faces a fundamental challenge due to the multitude of interconnected scales. Surfaces exhibit roughness with asperities occurring at various wavelengths. Only a small fraction of these asperities come into contact, and an even smaller fraction produces wear debris. The reasons behind why, how, and when this occurs are not fully understood. The debris gradually alter the surface profile and interacts with one another, either being evacuated from the contact interface or gripping it, leading to severe wear. Due to this challenge of scales, contributions of numerical studies in wear research over the past decades sum up to less than 1% (see Fig. 1). Yet, exciting opportunities exist for modeling, which we attempt to discuss here.

While analyzing a single asperity contact may not unveil the entire story, it arguably represents the most fundamental level to comprehend wear processes. This blog entry seeks to encapsulate the authors’ perspective on this rapidly evolving topic. Acknowledging its inherent bias, the aim is to spark controversies and discussions that contribute to a vibrant blogosphere on the mechanics of the process.

The subsequent section delves into the authors’ endeavors in modeling adhesive wear at the asperity level. Section 3 navigates the transition to abrasive wear, while Section 4 explores opportunities for upscaling asperity-level mechanisms to the meso-scale, with the aspiration of constructing predictive models. Lastly, although the primary focus of this blog entry is on modeling efforts, it would be remiss not to mention a few recent advances on the experimental front.

Daniel Mulvihill's picture

Postdoc in Mechanics/Tribology of Triboelectric Nanogenerators at University of Glasgow

Specifically, the post requires expert knowledge in experimental and/or computational mechanics of materials and/or tribology. The position is part of a large international EPSRC-SFI funded project aimed at developing next generation textile triboelectric nanogenerators (or T-TENGs) for powering of wearable electronics.  This position will focus on the mechanics and tribology of T-TENGs and will involve both modelling and experimental work.

Daniel Mulvihill's picture

Postdoc in Mechanics/Tribology and/or Triboelectric Nanogenerators

Postdoc position available on Mechanics/Tribology and/or Triboelectric Nanogenerators at the University of Glasgow's James Watt School of Engineering. Applicants with background in mechanics, tribology or triboelectric nanogenerators (including device fabrication and testing) are welcome. Closing date: 08-Dec-2020

carpick's picture

Postdoctoral Position: Oxide Nanoparticles as Lubricant Additives

THE SCHOOL OF ENGINEERING AND APPLIED SCIENCE at the UNIVERSITY OF PENNSYLVANIA invites applications for a full-time position as a Postdoctoral Researcher in the DEPARTMENT OF MECHANICAL ENGINEERING AND APPLIED MECHANICS in the laboratory of Prof. Robert W. Carpick (

marco.paggi's picture

New book on Modeling and Simulation of Tribological Problems in Technology, CISM series, Springer

The new book "Modeling and Simulation of Tribological Problems in Technology" (CISM book series, Springer) has been published:

Editors: Paggi, Marco (IMT School for Advanced Studies Lucca, Italy), Hills, David (University of Oxford)

Main contributing authors, lecturers of the CISM course D.A. Hills, J.R. Barber, M. Paggi, D. Dini, A. Almqvist 

Mike Ciavarella's picture

Is Tribology Approaching Its Golden Age? Grand Challenges in Engineering Education and Tribological Research

An interesting paper by VL Popov which suggests many problems of tribology are still very far from being remotely solved.  Despite the very detailed theories for example on rough contact using fractal surfaces on which we have debated mainly academically , there is not a single theory for any quantitative prediction of friction coefficient which can vary by 1 order of magnitude and its dependence on many variables, let alone wear coefficient which can vary up to 7 orders of magnitude.  What is left to do, other than measure?   Is tribology bound to be in practice just an experimental area? 

marco.paggi's picture

CISM course ''Modelling and Simulation of Tribological Problems in Technology''

Advanced Course at the International Centre for Mechanical Sciences (CISM, Udine, Italy)


Modelling and Simulation of Tribological Problems in Technology

May 28, 2018 — June 1, 2018 


Marco Paggi (IMT School for Advanced Studies Lucca, Lucca, Italy)

David A. Hills (University of Oxford, Oxford, Great Britain)

Cemal Basaran's picture

Scientists report solving one of the oldest problems in mechanics

Being able to accurately predict the life span of physical bodies, both living and non-living, has been one of humankind’s eternal endeavors.  Over the last 150 years, many attempts were made to unify the field of Newtonian mechanics  and thermodynamics,  in order to create a generalized and consistent theory of evolution of life-span.


Mike Ciavarella's picture

Lorentz Workshop "Micro/Nano Models for Tribology," Leiden, the Netherlands, 30/1-3/2/2017

We have organized a Lorentz Workshop with 60 selected partecipants leading scientists in tribology and contact mechanics mainly from Europe.

Attached a program.   Or see the web site

Micro/Nanoscale Models for Tribology (μ/n-Tribo-Models) 

Vladislav Yastrebov (co-organizer)

Lucia Nicola (co-organizer)

Annalisa Fasolino (co-organizer)

Michele Ciavarella (co-organizer)

Julien Scheibert (co-organizer)

Tenure-track Faculty at Eastern Michigan University in Tribology, Nanomechanics, or Solid Mechanics

The Depart­ment of Physics and Astronomy invites ap­plications for a tenure-track position in physics in the area of experimental nanomechanics/tribology starting Fall 2016. Re­spon­si­bilities include: teaching a full range of classes (from introductory to graduate level) in physics, especially mechanics; lead­ing mechanics-related activities; performing departmental service; and conducting scholarly activity. Minimum qualifications: A master's degree plus 18 semester hours.  Preferred qualifications: Ph.D.

Eran Bouchbinder's picture

Dynamic instabilities of frictional sliding at a bimaterial interface

Understanding the dynamic stability of bodies in frictional contact steadily sliding one over the other is of basic interest in various disciplines such as physics, solid mechanics, materials science and geophysics. Here we report on a two-dimensional linear stability analysis of a deformable solid of a finite height H, steadily sliding on top of a rigid solid within a generic rate-and-state friction type constitutive framework, fully accounting for elastodynamic effects.

pastewka's picture

CECAM Workshop "Chemical and structural transformations in materials under mechanical load"

We are pleased to announce a 4-day CECAM/Psi-k Workshop on

"Chemical and structural transformations in materials under mechanical load",

 that will take place at the EPFL campus in Lausanne from Tuesday 1st September to Friday 4th September 2015.

pastewka's picture

PhD Position in Computational Mechanics of Glasses, Karlsruhe Institute of Technology

Friction and wear are important processes that determine the function of many mechanical devices, but their underlying microscopic physical principles are complex and often not well understood. Amorphous – or glassy – materials often form on surfaces that have experienced frictional loading. The research will involve large-scale molecular dynamics simulation of the near-surface deformation upon indentation and scratching of network and bulk metallic glasses.

mohdfadzli's picture


It is our sincere pleasure to invite you to participate in the upcoming Malaysian International Tribology Conference 2015 (MITC2015). For quick information, feel free to watch our teaser at more details, you are kindly advice to visit our website at

NANOVEA's picture

Continuous Stribeck Curve Measurement Using Tribometer

Irvine, Calif., Oct 24, 2013 – Nanovea demonstrates for the first time the ability to measure a continuous Stribeck Curve. Using the Nanovea Tribometer advanced speed control, from 2000 to 0.01 rpm, within 10 minutes software monitoring provides a complete Stribeck Curve. Prior to this advancement a Stribeck Curve has been shown to be evaluated in a stepwise fashion requiring data stitching.

Mike Ciavarella's picture

Is wear law really Archard's law (1953), or Reye's law (1860) ???

In 1860 the mathematician and geometer Reye proposed a simple and elegant theory for explaining the consumption of a solid body when it slides with friction on a rough surface [8]. Reye’s model became very popular in Europe (in Italy was promulgated by Panetti [7]), and it is still taught in university courses of applied mechanics. But, strangely enough, this theory has been totally ignored in English and American literature.  Why? A paper from 2001 by Villaggio is interesting to read today.

Special Tutorial during WOM 2013: Fundamentals of Wear and Wear Testing

Taught by invited experts led by Professor Ian Hutchings, this popular half-day overview will be held on Sunday afternoon before the WOM 2013 conference Portland, Oregon, 14-18 April 2013.

The content is intended to help delegates who are new to the subject, or would like to refresh their background knowledge, and the lecturers aim to cover the general principles of wear and tribological testing. Printed notes will be provided for delegates.

The course outline includes:


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