Tribology (FSI-ZTR)

Students who pass the subject will be able to analyze, understand, and solve the primary problems of friction, lubrication, and wear in machine contacts.

• Knowledge of main principles, calculations, and rules for the design of contacts.
• Ability to apply gained knowledge in the design and development of new machines and equipment.
• Knowledge of methodology for selection and tribology testing of material combinations.
• Ability to solve tribological problems of lubricated or dry contacts, taking sustainability into account.

The subject provides theoretical and practical knowledge regarding processes of friction, lubrication, and wear which take place in machines with essential importance in design, production and maintenance. Attention is paid to students’ overview in the field, understanding of main principles, options for alternative ecological, sustainable solutions, engineering practice, and practical experience from laboratory measurements. The subject follows up and complements content of subjects in the Batchelor’s study in the fields of the mechanics, mechanical engineering and material sciences.

Conditions for obtaining credit:
- submission of a case study of the tribological system (max. 30 points).
Conditions for obtaining the final exam:
- multiple-choice test (max. 30 points),
- oral exam (max. 40 points),
- points for seminal work (max. 30 points),
- maximum possible points are 100, and final classification is given according to the ECTS scale.

Lectures: attendance is mandatory and checked by the teacher.
Exercises: participation is mandatory and checked by the teacher, with a maximum of two absences.
In the event of a long-term absence, compensation for missed classes is within the subject guarantor's discretion.

• Introduction to tribology, importance a historical development.


• Tribological system and processes. Principles and regimes of lubrication.


• Properties of solids and lubricants. Lubricants rheology.


• Lubricant types. Liquid lubricants and lubricant additives.


• Green tribology.


• Greases and solid lubricants.


• Contact mechanics. Hertzian theory. Measurements of surface topography. Contact between rough surfaces.


• Hydrodynamic lubrication. Reynolds Equation. Plain bearings. Hydrostatic lubrication.


• Elastohydrodynamic and mixed lubrication. Numerical modelling. Molecular dynamic simulation.


• Tribology of the wheel-rail interface.


• Boundary lubrication and boundary films.


• Tribology of thin layers, films and coatings. Dry lubrication.


• Friction, wear and tribotesting.


• Wear analysis.


• Tribological analysis of selected machine parts.

• Measurement of surface topography.


• Measurement of fluids viscosity.


• Measurement of hardness and load capacity of static point contact.


• Measurement of pressure field in hydrodynamically lubricated contact.


• Measurement of film thickness distribution in elastohydrodynamic contact.


• Measurement of Stribeck and traction curves.


• Measurement of wear rate.


• Tribology of wheel-rail contact.

• Viscosity, modelling of rheology and shear stress in lubricants.


• Hertzian contact problem. Load-carrying capacity of static contact. Contact stiffness.


• Hydrostatic and hydrodynamic lubrication.


• Regimes of lubrication, film thickness and film parameter prediction.


• Real contact area. Flash temperature.


• Fluid film friction.


• Wear rate. Coefficient of abrasive wear.