Dear visitor!

Welcome to the web-page dedicated to the Workshop "Micro/Nanoscale Models for Tribology" which was held in Lorentz Centre from January 30 to February 3, 2017 in Leiden. This web-page summarizes main outputs of the workshop (plenary lectures, round table dicussions) in order to provide you with an archival reference.

Workshop description

Tribological research at micro- and nanoscales is important for many cutting-edge engineering applications. However, the lack of cross-disciplinary communication within the experimental, theoretical and computational tribology communities has been an obstacle in answering fundamental questions about contact, friction and adhesion. Significant division lines can be found in the way we currently characterize surface roughness, as well as the methods by which we incorporate effects such as adhesion and plasticity in our analytical and computational models. Very often, our assumptions on these aspects severely limit the applicability of our models, their correspondence to realistic physical phenomena and their agreement with experimental results. Yet, even models that have received significant criticism are still in widespread use, suggesting that they are practically useful despite their (perceived) limitations. The proposed workshop aims to provide a forum for open discussion on these and other issues of critical importance to tribologists, both in academia and in industry, and beyond. In addition to fundamental understanding, successfully accounting for the effects of roughness, material and mechanical properties in our models will enable the design of surfaces and interfaces with entirely new properties, beyond the already explored self-cleaning or anti-fouling capabilities.

Objectives

• Addressing the following fundamental research questions:
1. What are the most accurate representations of roughness at the micro- and nanoscales, and how can these be meaningfully employed in analytical and computational models?
2. What are the roles of roughness and adhesion in metallic (elastic/ plastic) and polymeric (viscoelastic and adhesive) tribological interfaces?
3. What is the role of scale on plasticity and how does it affect contact and friction? At what scale size-effects become negligible?
4. How can we effectively bridge tribological models across the micro- and nanoscales?
5. How well do tribological models hold in the face of experimental evidence?
6. Are the model parameters currently and actually measurable in the lab?
• Tackling application-related research questions posed by participants from industry, or identifying these as key challenges for the field;
• Establishing a tentative research agenda based on unanswered fundamental questions and key challenges faced by the industry;
• Managing to initiate collaborations among the participants across scientific disciplines and between academia and industry;
• Providing a platform for young tribologists (PhDs, postdocs and new tenure-trackers) to showcase their research and interact with leading experts;
• Increasing the visibility of tribology in European academia and industry and promoting the tribology-related research performed at Dutch academic institutes.

Review paper

Plenary talks, round tables and general discussions permitted to write a rather complete review paper "Modeling and simulation in tribology across scales: An overview", which appeared in Tribology International, vol. 125, pp. 169-199 (2018), doi: 10.1016/j.triboint.2018.02.005

Abstract

This review summarizes recent advances in the area of tribology based on the outcome of a Lorentz Center workshop surveying various physical, chemical and mechanical phenomena across scales. Among the main themes discussed were those of rough surface representations, the breakdown of continuum theories at the nano- and microscales, as well as multiscale and multiphysics aspects for analytical and computational models relevant to applications spanning a variety of sectors, from automotive to biotribology and nanotechnology. Significant effort is still required to account for complementary nonlinear effects of plasticity, adhesion, friction, wear, lubrication and surface chemistry in tribological models. For each topic, we propose some research directions.

Poster

Photos

All photos taken by V. Yastrebov during the workshop are available in Gallery and also on photos.google.