Course detail
Fatigue of Aircraft Structures
FSI-OUZ-AAcad. year: 2024/2025
The course is concerned with the following topics: Safe-life and damage tolerance design concepts as two elementary approaches to provide the integrity of structure during its service life. Measurement of service loads, load spectra processing. Calculation of safe-life. Definition of typical flight profiles, S-N curve selection, fatigue damage accumulation hypotheses. Determination of safe-life based on fatigue tests of components and complete structure. Airworthiness requirements for damage tolerance aircraft structures, development of inspection program based on crack growth curves. Non-destructive testing techniques for aeronautical applications.
Language of instruction
Number of ECTS credits
Mode of study
Guarantor
Department
Entry knowledge
Rules for evaluation and completion of the course
Presence in the seminars is required. Missed seminars are compensated by elaboration of individual tasks.
Aims
Practical calculation of safe life of aircraft structure considering principal loads, load spectra treatment, selection of S-N curve. Overview of other topics concerning aircraft fatigue including experiences from fatigue tests carried out at the Laboratory of Institute of Aerospace Engineering.
Study aids
Prerequisites and corequisites
Basic literature
Farahmand, B.: Fatigue and Fracture Mechanics of High Risk Parts: Application of LEFM & FMDM theory. Chapman & Hall, 1997. (EN)
Schijve, J.: Fatigue of Structures and Materials, Springer Science+Business Media, B.V, 2010.
Recommended reading
Farahmand, B.: Fatigue and Fracture Mechanics of High Risk Parts, Chapman & Hall, 1997.
Schijve, J.: Fatigue of Structures and Materials, Springer Science+Business Media, B.V, 2010. (EN)
Classification of course in study plans
- Programme N-AST-A Master's 2 year of study, summer semester, compulsory
Type of course unit
Lecture
Teacher / Lecturer
Syllabus
2. Airworthiness requirements related to fatigue issues.
3. Phases of fatigue life. Fractographic reconstitution of fatigue crack growth.
4. Safe-life approach.
5. Typical flight profiles. Measurement and processing of load spectra. Gust, manoeuvre and ground loads spectra. Ground-air-ground cycle.
6. Fatigue curves of aircraft structures. Fatigue damage accumulation hypotheses.
7. Fatigue life prediction based on nominal and local approaches (NSA, LESA, LPSA). Multiaxial fatigue.
8. Fatigue tests and their evaluation. Constant-amplitude, program, variable-amplitude and flight-simulation fatigue tests. Fatigue testing machines.
9. Estimation of safe life by means of calculation and fatigue tests. Aircraft life monitoring systems.
10. Damage tolerance approach. Development of inspection program.
11. Overall review of NDT techniques. Requirements of JSSG-2006 and MIL-A-83444 standards.
12. Fundamentals of fracture mechanics. Residual strength analysis.
13. Crack growth under constant and variable-amplitude loading.
Exercise
Teacher / Lecturer
Syllabus
5. – 9. Calculation of safe-life of transport aircraft.
10. - 13. Calculation of propagation of fatigue crack in the wing panel skin.