Machine Design II

Syllabus

1. Modelling and Optimization (4 hours)
   1. Modelling: models (types, role in engineering design, mathematical modeling, similitude and scale models), finite element modeling and analysis
   2. Optimization techniques: differential calculus, search methods, multivariable search methods; linear and geometric programming, multifactor objective functions
2. Product Design Considerations (6 hours)
   1. Design for Manufacture and Assembly
   2. Design for Reliability and Safety
   3. Design for Quality and Robustness
   4. Design for Testing
   5. Design for Sustainability
   6. Risk, reliability and safety: risk and society, probabilistic approach to design, reliability theory (failure rates, system reliability), hazard analysis and fault tree analysis
3. Design of Springs (8 hours)
   1. Stresses in a helical spring
   2. Deflection of a helical spring
   3. Extension and compression springs
   4. Spring materials: estimation of tensile strength and torsional yield strength
   5. Design of helical spring: critical frequency
   6. Fatigue loading
   7. Belleville spring
   8. Helical torsion spring
   9. Leaf spring
   10. Energy storing capacity of a spring
4. Design of Spur and Helical Gears (12 hours)
   1. Lewis's bending equation
   2. Surface durability
   3. AGMA stress and strength equations
   4. Geometry factors, elastic coefficient and various factors affecting gear performance (dynamic, overload, surface condition, size, load distribution, hardness ratio, stress-cycle, reliability, temperature and rim-thickness factors)
   5. Safety factors
   6. Design of gear mesh
5. Design of Clutches and Brakes (10 hours)
   1. Internal expanding rim clutches and brakes
   2. External expanding rim clutches and brakes
   3. Band-type clutches and brakes
   4. Frictional contact axial clutches
   5. Cone clutches and brakes
   6. Energy consideration and temperature rise
   7. Frictional material
6. Design of Power Screws (5 hours)
   1. Power screws, forms of threads, multiple threaded screws, terminology
   2. Torque requirement for lifting and lowering loads, self-locking of screws
   3. Efficiency of power screws, collar friction torque, overall efficiency and coefficient of friction

Practicals

1. Solving problems related to the design of springs using computational tools
2. Computing problems related to the design of gear mesh (spur and helical) using computational tools
3. Computing problems related to the design of clutches and brakes using computational tools
4. Computing problems related to the design of power screws using computational tools

Evaluation

Final exam questions cover all chapters. Approximate marks distribution (total 60 marks over 45 hours):

1. Modelling and Optimization, Product Design Considerations: 14 marks
2. Design of Springs: 10 marks
3. Design of Spur and Helical Gears: 16 marks
4. Design of Clutches and Brakes: 14 marks
5. Design of Power Screws: 6 marks