Course

Unit 1

Introduction to Fracture Mechanics: Fundamentals of elasticity and plasticity theory, types of Failure, historical perspective, ductile, brittle fracture, Stress concentration effect of flaws, Griffith energy balance, the energy release rate (G), instability and resistance curve.
Stress analysis of cracks, Linear Elastic Fracture Mechanics (LFEM), modes of fracture, stress intensity factor, prediction, fracture toughness, crack tip plasticity, plastic zone, Dugdaleapproach

Unit 2

Elastic Plastic Fracture Mechanics (EPFM): Crack-Tip-Opening Displacement (CTOD), the J contour integral and its determination, relationships between J and CTOD, crack-growth resistance curves, J-controlled fracture.

Fracture mechanism in metals and non-metals: Ductile fracture, cleavage, the ductile-brittle transition, intergranular fracture, fracture in polymeric materials, and fracture in ceramic and ceramic composites.

Unit 3

Applications: Introduction to fracture toughness testing of metals and non-metals for determination of fracture parameters, Application of fracture mechanics concepts in the analysis of fatigue crack growth.

Computational fracture mechanics: Overview of numerical methods for fracture mechanics problems, traditional methods in computational fracture mechanics, finite element implementation, design of finite element mesh, linear elastic convergence study.

Course Objectives

• Familiarize with the basics of fracture mechanics
• Impart knowledge on strain energy release rate, stress intensity factor and J-integral and crack growth
• Expose students to various type of fracture and fracture parameters

Course Outcomes

• CO1: Apply principles of linear elastic fracture mechanics to solve for stress intensity factor and energy release rate of structures with cracks.
• CO2: Formulate J-integral and analyze stress-strain fields around a crack tip for non-linear material behavior.
• CO3: Classify the type of fracture and predict ductile to brittle transition.
• CO4: Estimate fatigue crack growth using principles of fracture mechanics.
• CO5: Predict stress intensity factor, energy release rate and J-integral, computationally, as per ASTM standards.

CO – PO Mapping

Textbook(s)

• Anderson, T. L., “Fracture Mechanics: Fundamentals and Applications”, 3/e, CRC Press, 2005.

Reference(s)

• Prashanth Kumar, “Elements of Fracture Mechanics”, McGraw Hill Education (India) Private Limited, 2009.
• Broek, D., “Elementary engineering fracture mechanics”. Springer Science & Business Media.2012.
• Knott J. K., “Fundamentals of Fracture Mechanics”, 3/e, Butterworth Heinemann, 1993.
• Suresh, S., “Fatigue of Materials”, 2e, Cambridge University Press, 1998.

Evaluation Pattern