Course: Technical Diagnostics

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Course title Technical Diagnostics
Course code KVM/TD
Organizational form of instruction Lecture + Lesson
Level of course Master
Year of study not specified
Semester Winter and summer
Number of ECTS credits 4
Language of instruction Czech, English
Status of course Compulsory, Compulsory-optional
Form of instruction Face-to-face
Work placements Course does not contain work placement
Recommended optional programme components None
Course availability The course is available to visiting students
Lecturer(s)
  • Tomeh Elias, doc. Dr. Ing.
Course content
A - Lectures and Consultations Thematic units: 1. Introduction of lectures for full time students: Vibrodiagnostics, Termovision, Tribodiagnostics. Use of Fourier's, Hilbert's, Laplace's Transformations for analyzing signals and systems. 2. Operational vibrations as a response to dynamic forces. Frequency calculation of primary sources of vibration excitation in machines and equipment. 3. Kinds of vibration excitation: kinematical, hydrodynamic, aerodynamic, electric, impulse and parametric. 4. Principle of the analyzer function: FFT, weight function, data frequency, averaging in frequencies and time signals. Spectrum, mutual and self spectrum, complex spectrum. 5. Operational balancing of rotors - stiff and elastic rotors, static and dynamic balancing. 6. Determination of the reasons and sources from measured vibration spectres. Spectres and cepsters of vibrations, spectral envelope. 7. Experimental modal analysis of manufactured systems. Modal frequencies and dumping, dynamic weight. 8. Frequencies characteristics of the system (linear and nonlinear system). Dynamic compliance, mobility and acceleration. 9. Conditions originating resonance in linear and nonlinear systems. Principles for measuring resonance in manufactured systems. 10. Place and benefits of measuring the Operational Deflection Shapes of vibrations. Computer animation of the system dynamic behaviour. 11. - 12. Basics of noise measuring: Parameters of noise - acoustic pressure, intensity of noise, Hygienic regulations. 13 - 14. Dynamic tuning of the system: Elimination of the resonance area by rectifying operational conditions, Decrease of excitation, unbalance, and misalignment, Elimination of parametric excitation of gear. B - Exercises: 1. Calculation of excitation frequency in given systems. Frequency modulation, Amplitude modulation and Phase modulation. 2. Measuring vibration spectres of machines according to the field of study. The influence of sensor fixation. 3. Operational balancing of the rotor. First report specification: Calculation of mobility, limit values of unbalance. 4. Measuring of self frequency and resonance in a chosen machine. Run on and run off characteristics, periodic impulse excitation, and random noise. Second task specification: Determining resonance run on and run off characteristics of a chosen machine. 5. - 6. Measuring modal parameters of a simple system. Third task specification: Modal analysis of a beam. 7. Operational deflection shapes. Analysis of a practical example. Costs and benefits. Measuring the operational shapes vibration in a car motor and car body. 8. Machine acceptance by vibration and noise measuring. EU regulations for industries. Life and reliability determination from vibration severity. 9. Normal and complex modes. Coherency. 10. Dynamic tuning of the system. Analysis of practical exercises, measuring after elimination of the problem causes. 11. - 13. Measuring the inside noise in a personal car. Vibration spectres of the motors and aggregates. Readability of the spoken word in the car's cabin during riding. 14. Identification of electrical problems in asynchronous electromotor. Spectres of vibrations and current supply.

Learning activities and teaching methods
Monological explanation (lecture, presentation,briefing), Self-study (text study, reading, problematic tasks, practical tasks, experiments, research, written assignments)
  • Class attendance - 28 hours per semester
  • Preparation for laboratory testing; outcome analysis - 28 hours per semester
Learning outcomes
The course focuses on the diagnosis of non-assembled machines. Diagnosis is mainly based on the measure-ment and vibration analysis of machines and equipment. Students will learn the vibration spectra, vibration cepstrum, vibration severity, determine the causes of excessive vibration, excitation frequencies, machines taking over, operating deflection shapes of oscillations, experimental modal analysis and termodiagnosis without disassembly. The subject contains the basics of noise measurement, noise reduction and detection of acoustic material properties such as acoustic absorption and transmission attenuation.
Students obtain knowledge in given course in accordance with requirements and course programme.
Prerequisites
Mechanics III (Dynamics), Machine Parts and Mechanisms, Mechanical vibrations

Assessment methods and criteria
Combined examination, Oral exam, Written exam

Graduation Requirements: - Attend minimally 85% of the practical exercises (in the case of higher excused absence, it is possible to set a reparation), work out and hand in an individual semestrial work to get the credit. - Pass an exam that includes a written part (about 60 minutes) and a spoken part (2 themes) to successfully graduate in the subject.
Recommended literature
  • BENEŠ, Š. :. Teorie stavby strojů. Stripta. Liberec, VŠST, 1986.
  • BENEŠ, Š. - TOMEH, E. :. Metody diagnostiky valivých ložisek. Skripta VŠST Liberec, Liberec 1991 2. BENEŠ, Š. : Teorie stavby strojů. Stripta VŠST v Liberci, Liberec 1986 3. BORŮVKA, V. : Provozní vyvažování rotorů 4. BROCH, J. T. : Mechanical vibration and shock measurement. Brüel & Kjaer, Dánsko 1984. 5. Brüel & Kjaer - firemní Příručky a Aplikační notesy 6. JULIŠ, K. - BREPTA, R. : Technický průvodce Mechanika II. SNTL, Praha 1987 7. NOVÝ, R. : Hluk a otřesy. Skripta ČVUT Praha. Praha 1995 8. RANDAL, R. : Frequency analysys. Brüel & Kjaer, Dánsko 1987 9. SMETANA, C. a kol. : Hluk a vibrace. Sdělovací technika. Praha 1998 10. TŮMA, J. : Zpracování signálů získaných z mechanických systémů užitím FFT. Sdělovací technika 1997. &, &.
  • BORŮVKA, V.:. Provozní vyvažování rotorů..
  • BROCH, J. T.:. Mechanical vibration and shock measurement. Brüel & Kjaer, Dánsko 1984..
  • Brüel & Kjaer:. Firemní Příručky a Aplikační notesy.
  • JULIŠ, K. - BREPTA, R. :. Technický průvodce Mechanika II. SNTL, Praha 1987..
  • NĚMEČEK, P. a E. TOMEH. Vibrační diagnostika základních závad strojů. Školicí skripta kurzu profesního vzdělávání. Bohumín: Diagnostický a technický institut Bohumín, 2007.
  • NOVÝ, R. :. Hluk a otřesy. Skripta ČVUT Praha. Praha 1995.
  • RANDAL, R. :. Frequency analysys. Brüel & Kjaer, Dánsko 1987.
  • SMETANA, C. a kol. :. Hluk a vibrace. Sdělovací technika. Praha 1998.
  • Tomeh, E.:. Diagnostic Methodlogy of Rolling Element and Journal Bearings. Technická univerzita v Liberci 2007.. TU v Liberci, 2007. ISBN 978-80-7372-278-4.
  • Tomeh, E.:. Přednášky TD. TU v Liberci, 2011.
  • Tomeh, E. Technická diagnostika: vibrační diagnostika strojů a zařízení. Liberec, 2015. ISBN 978-80-7494-174-0.
  • TŮMA, J.:. Zpracování signálů získaných z mechanických systémů užitím FFT. 1997..


Study plans that include the course
Faculty Study plan (Version) Category of Branch/Specialization Recommended year of study Recommended semester
Faculty: Faculty of Mechatronics, Informatics and Interdisciplinary Studies Study plan (Version): Automatic Control and Applied Computer Science (2016) Category: Special and interdisciplinary fields 2 Recommended year of study:2, Recommended semester: Summer
Faculty: Faculty of Mechatronics, Informatics and Interdisciplinary Studies Study plan (Version): Mechatronics (2016) Category: Special and interdisciplinary fields 2 Recommended year of study:2, Recommended semester: Summer