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SpeakersBenyebka BOU-SAID (INSA Lyon, LaMCoS)Introduction to tribology
Noël BRUNETIERE (CNRS, Univ. Poitiers, P'Prime)The lubrication mechanisms of textured surfaces
Surface texturing is known to improve the tribological performance of lubricated contacts: reduced friction and improved load-bearing capacity. This course will describe the mechanisms that ensure hydrodynamic load support for parallel surfaces. More specifically, the influence of the cavity aspect ratio (depth/width) on wetting behavior, fluid slippage along the wall, and the hydrodynamic effect will be discussed.
Jean BOUYER (CNRS, Univ. Poitiers, P'Prime)Reliability of hydrodynamic bearings in transmissions systems
After a short recall of Hydrodynamic lubrication in journal bearings (basic principles, lubricants, materials), I will discuss about the failure modes in a journal bearing and their causes and how to treat this at the stage of design.
Huseyin CIMENOGLU (Istanbul Teknik Universitesi)Wear of Metal Forming Dies Metal forming dies are commonly subjected to a combination of impact and sliding forces, resulting in contact pressures > 1 GPa, throughout their service lives. Simulating their working conditions in a laboratory appears to be an easier, shorter and cheaper approach to explore the roles of die material, bulk and surface hardening treatments etc., on the progress of wear, compared to field tests. In the scope of the lecture, primarily the details of the impact -sliding wear tests employed on a hot work die steel with the aim of optimising gas nitriding parameters will be presented. Secondly, results of impact-sliding wear tests conducted on two different cold work die steels with identical hardness will be discussed to reveal the role of microstructural features on the service performance of trimming dies
Demirkan COKER (Middle East Technical University - Ankara)Interfacial Friction: From Roughness Effects to Rupture Front Propagation This lecture focuses on the mechanics of friction along interfaces between plates. In the first part, the effect of surface roughness and its evolution on the stability of frictional sliding is presented through modeling and experimental results. In the second part, the dynamics of interfacial rupture phenomena are presented, emphasizing that frictional sliding occurs through propagating rupture in the form of enlarging cracks or slip pulses. Rate- and state-dependent friction models are used as the constitutive basis for describing the evolution and dynamics of interfacial slip.
Martin DIENWIEBEL (Karlsruhe Institute of Technology)Formation of Third Bodies in dry and in lubricated conditions
Malal KANE (Univ. Gustave Eiffel)Pavement friction: Pavement Friction and Road Safety: Tribological Mechanisms and Performance Evolution
This course provides an in-depth understanding of pavement friction as a key factor in road safety. It explores the tribological mechanisms governing tire–pavement interaction, including adhesion, hysteresis, surface texture effects, and wear processes. Particular emphasis is placed on the multi-scale nature of contact, from microtexture to macrotexture, and on how traffic loading and environmental conditions influence friction performance over time. The course also presents experimental characterization methods and modelling approaches used to analyse and predict friction evolution. By linking fundamental tribology to practical road safety challenges, participants will gain a comprehensive and research-oriented perspective on pavement performance and durability.
Francesco MASSI (La Sapienza, Univ. Roma)Tribology and dynamics, Friction-Induced Vibrations in dry contacts
The lecture will deal with the strong coupling between interface dynamics and structural dynamics and the impacts on the tribological response of dry contacts.
Guillermo MORALES ESPEJEL (SKF, INSA Lyon)Surface Life Challenges in Machine Elements
The presentation outlines the main challenges that rolling/sliding surfaces in conformal contacts face withing the context of industrial mega-trends. The main focus is to describe modelling strategies to map the different damaging modes, e.g. wear, surface fatigue and adhesive wear and the integration of these damaging modes into the life of a full contact and eventually a machine element.
Michael MOSELER (Univ. Fribourg)Digital twins for tribological contacts under boundary and mixed lubrication conditions
This lecture elaborates on the hypothesis that the Reynolds lubrication equation works down to sub-monolayer lubricant films allowing for the construction of a digital twin that quantitatively describes all microscale lubrication regimes in engineering sliding contacts – from boundary to hydrodynamic lubrication. Such a non-empirical continuum-physics-based digital twin would revolutionize the design and operation of sliding contacts in machines. Today, reliable continuum models of thermo-elasto-hydrodynamic lubrication (TEHL) are routinely used for component design. However, these standard TEHL models are considered to be invalid when the sliding surfaces are not separated by a thick enough lubricant film. I will show that TEHL can then still be applied provided constitutive equations (CEs) are employed that consider finite-size effects such as slip and lubricant layering at walls. This is achieved by a massive effort to produce a variety of atomistic benchmark data by molecular dynamics (MD) with non-reactive force fields for the lubricant rheology. Coarse-grained large-scale MD of lubricated µm-sized surfaces and high-throughput all-atom MD for nm-sized parallel channels allow for an effective validation and training of novel physics-based CEs for an extended TEHL model. This makes the digital twin a predictive tool linking nanoscale molecular structure of constituents to the friction of components at the macroscale. The final goal is to quantitatively describe lubrication in tribological experiments under high loads and to predict optimal conditions for super-low friction and wear in energy-efficient and sustainable machines.
Aurélien SAULOT (INSA Lyon, LaMCoS)Wheel-rail contact: a tribological antagonism
The presentation will focus on the fundamental phenomena of wheel-rail contact, including flange lubrication, top-of-rail friction, fatigue and wear. Some case studies on wheel-rail contact will be presented: squat defect, leaf pollution,...
Bilsay SUMER (Istanbul Teknik Universitesi)Smart Tribology: Advanced sensors, data fusion ans artifial intelligence
This lecture presents an integrated perspective on advanced instrumentation, multi-parameter sensing, and emerging artificial intelligence (AI) techniques in modern tribology. The talk will cover high-precision measurement strategies for friction force, wear rate, contact temperature, vibration and surface deformation using multi-axis load cells, torque sensors, flexible tactile sensors, thermocouples, displacement/acceleration sensors and acoustic emission sensors embedded within tribometers and custom experimental platforms. Emphasis will be placed on sensing principles, calibration methodologies, signal conditioning, uncertainty quantification and the challenges of capturing transient and nonlinear contact phenomena. In addition, the lecture will introduce data-driven approaches-includinf Artificial Neural Networks (ANN), Support Vector Machines (SVM), and deep learning architectures such as LSTM networks- for anomaly detection in machines. By demonstrating how multi-sensor data fusion combined with AI enhances real-time diagnostics and predictive maintenance, the lecture aims to outline a roadmap toward intelligent, autonomous tribological systems for advanced mechanical and aerospace applications. |
