ECTS credits
2 credits
Semester
Fall
Prerequisites
• MMC, tensor algebra and analysis
• Elastoplastic behavior (see 3rd year Material behavior - Plasticity course)
• Beam model (see 3rd year Thin structures ans instablities course)
Learning objectives
• Discover the classical approaches of linear fracture mechanics
• Discover the main characteristics of the fatigue phenomenon of materials and structures on simple examples
• Know the classical approaches to fatigue called "uniaxial" and discover the current approaches to fatigue (multiaxial)
• Acquire the concepts and calculation methods used in yield design and limit analysis
Description of the programme
• Part 1: Phenomena and Models
-- Linear fracture mechanics: validity domain and typical problem
-- Global approach to fracture: energy restitution rate and Griffith criterion
-- Local approach to fracture: stress intensity factors and K1c criterion
-- Comparison between the two classical approaches in linear fracture mechanics
-- Influence of the loading path (monotonic or cyclic) on the fracture behavior of solid of solid structures: phenomenology and classification
-- Uniaxial" fatigue with a large number of cycles: Wöhler curve and Haigh diagram; Paris law
-- Uniaxial" fatigue at small number of cycles (oligocyclic): Manson-Coffin law
-- Multiaxial fatigue at large number of cycles: macroscopic criterion of Sines and macro-micro of Dang Van
• Part 2: Yield design and limit analysis
-- Notions of limit loads and plastic failure mechanisms: examples of a lattice of bars and a cylindrical shaft in torsion
-- Theory of yield design: notion of resistance criterion of materials, maximum resisting work and static approach for the calculation of loads potentially bearable by a structure
-- Dual kinematic approach
-- Notion of safety coefficient
-- Application to beam structures, notion of plastic hinge in bending
Generic central skills and knowledge targeted in the discipline
• Know the failure mechanisms
• Know the main criteria of failure
• Know how to determine the mechanisms that can lead to the failure of a given system
• Know how to dimension a structure with respect to yield design
How knowledge is tested
• DS1 : written evaluation of 1 hour on the 1st part (50%)
• DS2 : written evaluation of 1 hour on the 2nd part (50%)
Bibliography
• J. Garrigues, Cinématique des milieux continus (en ligne)
• J. Lemaître et J.-L. Chaboche, Mécanique des matériaux solides, éd. Dunod, 2004
• D. François, A. Pineau et A. Zaoui, Viscoplasticité, endommagement, mécanique de la rupture, mécanique du contact, éd. Lavoisier, 2009
• J. Salençon, Calcul à la rupture et analyse limite, Presses de l’ENPC, 1983
Teaching team
• Thierry Désoyer
• Stéphane Bourgeois
- Total hours of teaching24h
- Master class18h
- Directed work6h