Tribology (FSI-ZTR)

Students after passing the subject will be able to analyse, understand and solve main problems of friction, lubrication and wear of contacts in machines.

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

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

Lectures: attendance is mandatory and checked by the teacher.
Exercises: participation is mandatory and checked by the teacher, maximum two absences.
In case of long-term absence, compensation for missed classes is in the competence of the subject guarantor.

• 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. 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 compliant contacts.


• 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.