Machine Design : Theories of failure and Design for fatigue

Learn about the Theories of mechanical failure and principles of designing for fatigue for mechanical engineering

Machine design is the practice of designing structural elements of a product to meet functional and durability criteria .

Failure prevention is a big part of study for Machine design . This course deals with the various theories of failure in Static and dynamic (cyclic) loading conditions.

• Basics of Principal stress from mechanics of materials

• Importance of principal stress

• What are Theories of failure? the most simplest form

• Maximum Shear stress Theory - How it is derived , the analysis and cases

• Maximum distortion Energy theory - the most widely used theory of failure for ductile materials

  • The derivation from concept of strain energy

  • Definition of Von mises stress

• Mohr theory - Theory for materials with different tensile and compressive strengths

• Coulomb- Mohr theory

• Brittle Failure theory

• Selection of Failure theory

• What is Fatigue loading? fatigue failure?

• Fracture mechanics basics

• What is fracture toughness property

• Factors to be considered

• The S-N curve and RR Moore test to develop S-N curve

• Endurance strength and Endurance limit

• The Endurance limit modifying factors

  • Surface, Size, temperature, loading

• Stress concentration factor

• Characterization of cyclical loading

• Definition of failure criteria in Fatigue

The course is designed to be compact and to the point highlighting the most important concepts and the Why ? behind it.

This is an advanced level course suitable if you are already familiar with strength of materials or mechanics of materials and basics of mechanical engineering .