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Fracture mechanics

Type of study Follow-up Master
Language of instruction English
Code 653-3005/02
Abbreviation LMn
Course title Fracture mechanics
Credits 6
Coordinating department Department of Materials Engineering and Recycling
Course coordinator prof. Ing. Bohumír Strnadel, DrSc.

Osnova předmětu

1. Historical introduction and significance of fracture mechanics. Examples of structures damaged by crack or fractures.
2. Summary of the basic principles and concepts of the theory of elasticity. The stress concentrations in the vicinity of notches or holes.
3. The elastic stress field at the crack tip. Mathematical solutions. Mod (I-III) and the use of stress intensity factors. The influence of external multi-axial stress, superposition principle. Effect of finite dimensional elements, shape functions (factors).
4. Plastic zone at the crack tip, the size of the zones and the differences between the plane stress and plane strain state. Redistribution of stresses. The importance of plastic zones.
5. Mechanisms of initiation and growth of cracks.. Maps of fracture mechanisms. Methods of study of fractures, fractography, metallography.
6. Fracture toughness KIc, its determination to standards. The range of KIc values for materials, Ashby maps. Options of determine the critical stress or crack size. Effects of the structure of the material, temperature and thickness of the parts to the values Kc.
7. Energy approaches. Griffith´s theory. The driving force (energy) G of crack, crack propagation resistance R. Sih strain energy density factor and its applications. Critical values of stated parameters. Relations among fracture mechanics parameters.
8. Dynamics of fracture and crack arrest. The effect of shock loads and waves on crack. Impact testing of materials. Unstable crack propagation and the possibility of crack arrest.
9. Transit behaviour of metallic materials. Testing and determination of transition temperatures (DWT, DT, CAT). Standards and use in practice.
10. Nonlinear elastoplastic fracture mechanics. Crack opening displacement (COD), methods of measurement. Determination J-integral, its application examples.
11. Application of fracture mechanics to the growth of fatigue cracks. Paris relationship and possibility of prediction of cyclic life.
12. Crack growth under stress corrosion cracking and hydrogen embrittlement conditions. Application of LM parameters and thresholds values.
13. Calculation of critical defect size and service life of structures. Examples of pressure vessels and piping. Diagnosis of cracks.
14. Catastrophic fractures in practice, case study. The use of fractography in the analysis of material failure.

Povinná literatura

ANDERSON, T. L. Fracture Mechanics. Fundamentals and applications. 4th ed. London: CRC Press, 2005. ISBN 978 142 0058215 .

FELBECK, D. K. and A. G. ATKINS. Strength and Fracture of Engineering Materials. 1st. ed. Englewood: Prentice Hall, 1984. ISBN 0-13-851709-6.

CHIN-TECH, S. Fracture mechanics. 1st ed., Cambridge: Academic Press, Elsevier, 2012. ISBN 9780123850027 .

Doporučená literatura

LASEK, S. Fracture Mechanics. Ostrava: FMMI VŠB-TU Ostrava, 2015. Available from:

http://katedry.fmmi.vsb.cz/Opory_FMMI_ENG/AEM/Fracture%20mechanics.pdf

Engineering Fracture Mechanics. E- journal. Available from:: https://www.journals.elsevier.com/engineering-fracture-mechanics