Course: Structural Mechanics of Fibrous Assemblies

» List of faculties » FT » KTT
Course title Structural Mechanics of Fibrous Assemblies
Course code KTT/D137
Organizational form of instruction Lecture
Level of course Doctoral
Year of study not specified
Semester Winter
Number of ECTS credits 0
Language of instruction Czech, English
Status of course Compulsory-optional
Form of instruction Face-to-face
Work placements Course does not contain work placement
Recommended optional programme components None
  • Neckář Bohuslav, prof. Ing. DrSc.
Course content
- Modeling of fiber orientation in 3D and 2D. General relations of orientation, orientation in sectional plane. Mean sectional area of one fiber, coefficient, number of fibers in a section. Phenomenological model of orientation in 2D, orientation in web and fleece. - Fiber-to-fiber contacts. Theory of random contacts (van Wyk), density and distances of contacts, generalization of theory (mutual "obstruction" of fibers). Probability density function of contact places on 3D and 2D. - One-dimensional compression of fibrous assembly. General theoretical solving and simplified variant (van Wyk), correction for very small and very high pressures, possibilities of generalization to more-axial compression. - Tenacity and breaking strain of bundle from more components. Generalization of Hamburger's theory, finding of algorithm of calculation. - Tenacity and breaking strain of bundle from fibers having variable properties. Model solving, containing variable values of fiber strength, fiber breaking strain, and fiber crimp. - Tensioning of multi-axial fibrous assembly. General solving by finite number of fiber layers, case of regular multiaxial textiles (mechanical anisotropy). Modeling of fiber assembly with continuous distribution of directions. - Yarn strength and gauge length. Principle of weakest link, solving for mutually independent strengths of short yarn parts (Gauss, Weibull). Solving for depend strengths of short yarn parts (Markovian process). Note: Previous mathematical models are relatively complicated and large. Doctoral students are oriented primarily to thematic spheres relating to their themes of theses.

Learning activities and teaching methods
Monological explanation (lecture, presentation,briefing), Dialogue metods(conversation,discussion,brainstorming), Self-study (text study, reading, problematic tasks, practical tasks, experiments, research, written assignments), Independent creative and artistic activities
Learning outcomes
The subject is oriented to mathematical (deterministic and/or stochastic) modeling of basic structural relations in fiber assemblies and to following effects in their mechanical behaviors.
The student will acquire detailed knowledge of the subject in the area according to the approval of the Branch Board

Assessment methods and criteria
Oral exam

oral examination before a committee appointed by the Dean. Written work in the recommended range of 20 pages.
Recommended literature
  • Hearle, J. W. S., Grosberg, P., Backer, S. Structural mechanics of fibers, yarn and fabrics. USA, 1969.
  • Kovář, R. Struktura a vlastnosti plošných textilií. Skriptum, TUL. Liberec, 2003.
  • Neckář B. , Ibrahim S. Structural theory of fibrous assemblies and yarns. Part 1.. TU Liberec, 2003.
  • Neckář, B. Morfologie a strukturní mechanika obecných vlákenných útvarů. Skriptum TU Liberec. (Jen vybrané části.). TU Liberec, 1998.
  • Neckář, B. Příze - tvorba, struktura, vlastnosti. Praha, 1990.
  • Postle R. and all. The mechanics of wool structures. New York, Brisbane, Toronto, Sydney, Toronto, 1988.
  • Žurek W. Struktura liniowych wyrobow wlokienniczych. Warszawa, 1989.

Study plans that include the course
Faculty Study plan (Version) Category of Branch/Specialization Recommended year of study Recommended semester