Introduction: Design Process: Definition of design, phases of design, and review of engineering materials and their properties and manufacturing processes; use of codes and standards, selection of preferred sizes. Review of axial, bending, shear and torsion loading on machine components, combined loading, two- and three dimensional stresses, principal stresses, stress tensors, Mohr's circles.
Design for static strength: Factor of safety and service factor. Failure mode: definition and types. , Failure of brittle and ductile materials; even and uneven materials; Theories of failure: maximum normal stress theory, maximum shear stress theory, distortion energy theory, strain energy theory, Columba –Mohr theory and modified Mohr’s theory. Stress concentration, stress concentration factor and methods of reducing stress concentration.
Impact Strength: Introduction, Impact stresses due to axial, bending and torsion loads.
Fatigue loading: Introduction to fatigue failure, Mechanism of fatigue failure, types of fatigue loading, S-N Diagram, Low cycle fatigue, High cycle fatigue, Endurance limit. Modifying factors: size effect, surface effect, Stress concentration effects Notch sensitivity, Soder berg and Goodman relationships, stresses due to combined loading, cumulative fatigue damage, and Miner’s equation.
Design of shafts: Torsion of shafts, solid and hollow shaft design with steady loading based on strength and rigidity, ASME and BIS codes for power transmission shafting, design of shafts subjected to combined bending, torsion and axial loading. Design of shafts subjected to fluctuating loads
Design of keys and couplings: Keys: Types of keys and their applications, design considerations in parallel and tapered sunk keys, Design of square and rectangular sunk keys. Couplings: Rigid and flexible coupling-types and applications, design of Flange coupling, and Bush and Pin type coupling.
Design of Permanent Joints: Types of permanent joints-Riveted and Welded Joints.
Riveted joints: Types of rivets, rivet materials, Caulking and fullering, analysis of riveted joints, joint efficiency, failures of riveted joints, boiler joints, riveted brackets.
Welded joints: Types, strength of butt and fillet welds, eccentrically loaded welded joints
Design of Temporary Joints: Types of temporary joints- cotter joints, knuckle joint and fasteners. Design of Cotter and Knuckle Joint.
Threaded Fasteners: Stresses in threaded fasteners, effect of initial tension, design of threaded fasteners under static, dynamic and impact loads, design of eccentrically loaded bolted joints.
Power screws: Mechanics of power screw, stresses in power screws, efficiency and self-locking, design of power screws.
Assignment:
Course work includes a Design project. Design project should enable a group of students (maximum four in a group) to design a mechanical system (like couplings, screw jack, welded joints, bracket mounting using fasteners, etc.). Student should submit assembly drawing and part drawings, completely dimensioned, indicating the necessary manufacturing tolerances, surface finish symbols and geometric tolerances wherever necessary. Design project must be completed using appropriate solid modeling software. Computer generated drawings must be submitted. Design calculations must be hand written and should be included in the report. Design project should be given due credit in internal assessment.
Course Outcomes:
At the end of the course, the student will be able to:
CO1: Apply the concepts of selection of materials for given mechanical components.
CO2: List the functions and uses of machine elements used in mechanical systems.
CO3: Apply codes and standards in the design of machine elements and select an element based on the Manufacturer’s catalogue.
CO4: Analyse the performance and failure modes of mechanical components subjected to combined loading and fatigue loading using the concepts of theories of failure.
CO5: Demonstrate the application of engineering design tools to the design of machine components like shafts, couplings, power screws, fasteners, welded and riveted joints.
CO6: Understand the art of working in a team.
Question paper pattern:
Textbook/s
1 Shigley's Mechanical Engineering Design Richard G. Budynas, and J. Keith Nisbett McGraw-Hill Education 10th edition, 2015.
2 Fundamentals of Machine Component Design Juvinall R.C, and Marshek K.M. John Wiley & Sons Third Edition, 2007 student edition
3 Design of Machine Elements, V B Bhandari Tata McGraw Hill 4th Ed., 2016.
4 Design of Machine Elements-I Dr.M H Annaiah Dr. J Suresh Kumar Dr.C N Chandrappa New Age International (P) Ltd., 1s Ed., 2016
Reference Books
1 Machine Design- an integrated approach Robert L. Norton Pearson Education 2nd edition.
2 Design and Machine Elements Spotts M.F., Shoup T.E Pearson Education 8th edition,2006
3 Machine Component Design Orthwein W Jaico Publishing Co 2003
4 Machine Design Hall, Holowenko, Laughlin (Schaum’s Outline series) adapted by S.K.Somani Tata McGraw Hill Publishing Company Ltd Special Indian Edition, 2008
5 Elements of Machine Design H.G.Patil, S.C.Pilli, R.R.Malagi, M.S.Patil IK International First edition,2019
6 Design of Machine Elements Volume I T. Krishna Rao IK international publishing house, New Delhi. 2012
7 Hand book of Mechanical Design G. M. Maithra and L.V.Prasad Tata McGraw Hill 2nd edition, 2004.
Design Data Hand Book:
[1] Design Data Hand Book, K. Lingaiah, McGraw Hill, 2nd edition, 2003.
[2] Design Data Hand Book, K. Mahadevan and Balaveera Reddy, CBS publication.
[3] Design Data Hand Book, H.G.Patil, I. K. International Publisher, 2010
[4] PSG Design Data Hand Book, PSG College of technology, Coimbatore.