Credits: 3 (3–0–0)
Description
Linear elastic fracture mechanics (LEFM) and Elastic plastic fracture mechanics (EPFM). Theoretical cohesive strength. Energy based approach to fracture. Griffiths crack theory. Energy release rate: compliance and strain energy approach. Critical energy release rate and toughness. Stress field around a crack: Modes I, II and III. Plane strain and plane stress. Effect of plate thickness. Stress intensity factor. Critical stress intensity factor and fracture toughness. Plastic deformation near the crack tip. Approximate plastic zone size based on von-Mises and Tresca yield criteria. Irwin and Dugdale approaches. Effective crack size. J-Integral: definition and path independence. Equivalence of J, G and K. Crack-tip opening displacement. Fracture toughness testing. Ductile-brittle transition, impact energy fracture toughness correlation. Cyclic stress and strain fatigue. Fatigue crack propagation, analysis of engineering failures. Microstructural aspects of fracture toughness. Environmental assisted cracking. Mixed mode crack initiation and growth.