Course detail

Tribology

FSI-ZTR Acad. year: 2024/2025 Summer semester

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 on student’s overview in the field, understanding of main principles 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.

Language of instruction

Czech

Number of ECTS credits

5

Supervisor

prof. Ing. Martin Hartl, Ph.D.

Department

Institute of Machine and Industrial Design

Entry knowledge

Knowledge from material sciences, strength of materials, machine design and hydrodynamics.

Rules for evaluation and completion of the course

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.

Aims

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.

The study programmes with the given course

Programme N-KSI-P: Mechanical Engineering Design, Master's, compulsory

Programme C-AKR-P: , Lifelong learning
specialization CLS: , elective

Type of course unit

 

Lecture

16 hours, compulsory

Syllabus


  • 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.

Laboratory exercise

16 hours, compulsory

Syllabus


  • 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.

Computer-assisted exercise

16 hours, compulsory

Syllabus


  • 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.