Unit 1

Introduction to Linear and Elasto-plastic fracture mechanics (FM), historical development of FM, modes of fracture, crack growth mechanisms, brittle and ductile fracture behaviour. study on energy release rate (G), derivation of ‘G’ on Double cantilever beam, Energy release rate derivation on different modes of failure, Necessary and sufficient conditions of FM and stable and unstable fracture mechanisms.

Unit 2

Introduction to stress to intensity factor, K, (SIF)– Cauchy- Riemann conditions, Westergaard’s stress function, stress intensity factors derivations for different failure modes. Determination of crack-tip stresses and displacement field, principal of superposition – study on K and G relation. SIF of surface and embedded cracks.

Unit 3

Determination of Crack Opening Displacement (CTOD/COD). Energy release rate by J-integral approach, Evaluation of failure energy by numerical approach. Study on different fracture toughness tests: plane strain test, Compact tension test, three-point bending test, C-specimen test, Chevron notch test.

Course Objectives

• Introduce the physical and mathematical principles of linear and nonlinear fracture mechanics and their applications in wide range of engineering design using energy release rate and stress intensity approaches. This course will expand the student knowledge on use of finite element software to design fracture problems.

Course Outcomes

• CO1: Illustrate the types of fractures with characteristic features and different growth mechanisms.
• CO2: Understanding the principles of energy release rate and determining the energy release rate on different failure modes.
• CO3: Determination of stress intensity factor (SIF) for plane, surface and embedded cracks under various types of loads.
• CO4: Study of J-Integral approach to determine fracture energy and introduction to CTOD method.
• CO5: Identifying the various testing procedures to determine fracture toughness.

CO – PO Mapping

Textbook(s)

• Anderson, T.L., “Fracture Mechanics”, 2^nd Edition, CRC Press, 1995.

Reference(s)

• Ramesh, K., “e-book on Engineering Fracture Mechanics”, IIT-Madras publisher.
• Prashant Kumar, “Elements of Fracture Mechanics” Tata McGraw-Hill Education, 2009.

Evaluation Pattern