17ME752 Fracture Mechanics syllabus for ME

Fracture mechanics principles:

Introduction and historical review, Sources of micro and macro cracks. Stress concentration due to elliptical hole, Strength ideal materials, and Griffith’s energy balance approach. Fracture mechanics approach to design, NDT andVarious NDT methods used in fracture mechanics, Numerical problems. The Airy stress function. Effect of finitecracksize. Elliptical cracks, Numerical problems.

Plasticity effects:

Irwin plastic zone correction. Dugdale’s approach. The shape of the plastic zone for plane stress and plane strain cases.Theplate thickness effect, numerical problems.Determination of Stress intensity factors and plane strain fracture toughness: Introduction, estimation of stress intensity factors. Experimental method- Plane strain fracture toughness test, The Standard test,sizerequirements,etc.

The energy release rate,

Criteria for crack growth. The crack resistance(R curve). Compliance.Tearingmodulus.Stability.

Elastic plastic fracture mechanics:

Fracture beyond general yield. The Crack-tip opening displacement. The Use of CTOD criteria. Experimental determination of CTOD. Parameters affecting the critical CTOD.

J integral:

Use of J integral. Limitation of J integral. Experimental determination of J integral and the parameters affecting J integral.

Dynamics and crack arrest:

Crack speed and kinetic energy. Dynamic stress intensity and elastic energy release rate. Crackbranching. Principles of crack arrest. Crack arrest in practice. Dynamic fracture toughness.

Fatigue crack propagation and applications of fracture mechanics:

Crack growth and the stress intensity factor. Factors affecting crack propagation. Variable amplitude service loading, Means to provide fail-safety, Paris law, Required information for fracture mechanics approach,

Course outcomes:

• Develop basic fundamental understanding of the effects of cracklike defects on the performance of aerospace, civil, and mechanicalEngineering structures.
• Learn to select appropriate materials for engineering structures to insure damage tolerance.
• Learn to employ modern numerical methods to determine critical crack sizes and fatigue crack propagation rates in engineering structures.
• Gain an appreciation of the status of academic research in field of fracture mechanics.

TEXT BOOKS:

1 Elements of Fracture Mechanics by Prasant Kumar, Mc Graw Hill Education, 2009 Edition

2. Anderson , “Fracture Mechanics-Fundamental and Application”, T.L CRC press1998.

3. David Broek, “Elementary Engineering Fracture Mechanics”, Springer Netherlands,2011

REFERENCE BOOKS

1. Karen Hellan , “Introduction to fracture mechanics”, McGraw Hill, 2nd Edition

2. S.A. Meguid , “Engineering fracture mechanics” Elsevier Applied Science, 1989

3. Jayatilaka, “Fracture of Engineering Brittle Materials”, Applied Science Publishers, 1979

4. Rolfe and Barsom , “Fracture and Fatigue Control in Structures” , Prentice Hall, 1977

5. Knott , “Fundamentals of fracture mechanisms”, Butterworths, 1973