ME 484
FRACTURE OF MATERIALS

Course Description

Fracture mechanics and fatigue mechanisms: mechanisms of ductile and brittle fracture. Environmentally induced fracture and fatigue. Considerations in design of engineering materials and structures will be discussed.

Topics

• Introduction, elasticity
• Stress concentrations, Griffith theory, strain energy release rate, stress analysis, stress intensity
• Stress intensity, superposition, crack tip plasticity, plane stress/strain, plastic constraint, critical crack size
• G vs. K, CTODs, KIc testing, R-curves
• R-curve testing, elastic-plastic fracture mechanics (EPFM), J-integral, JIc testing, fracture mechanisms
• Ductile and brittle fracture, DBTT, toughening mechanisms, extrinsic vs. intrinsic toughening
• Crack bridging, embrittlement, environmentally assisted cracking growth
• Environmentally assisted crack growth, fatigue: (S/N) approach, crack initiation
• Fatigue: damage tolerant approach, crack growth, life prediction, da/dN-DK testing, crack growth mechanisms, fatigue markings
• Crack closure, brittle material fatigue, crack size effects

Learning Outcomes

The student, upon completion of this course, will be able to:

• Correctly apply fracture mechanics to predict material failure.
• Identify and describe the basic fracture and fatigue mechanisms.
• Correctly predict fatigue life using S/N and fracture mechanics based methods.
• Correctly identify the cause of failure of a material based on fracture surface observations.