JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Course Objectives:

• 1. To study the different types of fatigue failures and their mechanisms in the engineering applications
• 2. To study the basic theory of fracture mechanics and its relationship with fatigue and creep failure mechanisms
• 3. To understand the damage tolerance approach in the life estimation of structures Course outcomes: After completing this course, the student will have:
• 1. The ability identify the characteristic fatigue failures in the engineering structures
• 2. Knowledge of connecting fracture mechanics concepts to fatigue failure
• 3. Knowledge of fatigue failure mechanisms in non-metallic materials

UNIT - I

Introduction and historical overview, Types of fatigue – low cycle fatigue, high cycle fatigue, very high cycle (giga cycle) fatigue, Fatigue test methods and equipment, Total life approaches based on cyclic stress and cyclic strain, Cyclic hardening and softening in single crystals and polycrystals

UNIT - II

Crack initiation and propagation, Mechanisms, Macrostructural and microstructural aspects, Use of fracture mechanics in fatigue.

UNIT - III

Local strain approach, effect of different factors on fatigue – Stress concentration, Size, Surface, Temperature, Frequency, Environment, Microstructure, Residual stresses, Fretting, Creep-fatigue interaction, Multi axial stresses, Thermo mechanical loading, Variable amplitude loading, Load sequence, Crack closure.

UNIT - IV

Fatigue behaviour of different materials – Metallic materials and weldments, Ceramics, Polymers, Composites, Metallic glasses, Shape memory alloys,

UNIT - V

Fatigue behaviour of ultrafine grained materials, Nano crystalline materials, Biomaterials, Metallic foams Case studies on fatigue failures, Design considerations, Methods for fatigue life improvement

TEXT BOOKS:

• 1. Fatigue of Materials, Suresh, Cambridge India, 2015
• 2. Fracture Mechanics, Fundamentals and Applications, T.L. Anderson, CRC Press 2017

REFERENCE BOOKS:

• 1. Dieter
• 2. Thomas. H. Courtney R18 B.TECH MME III YEAR