Course

Unit 1

Introduction to the design process – factors influencing machine design, selection of materials based on mechanical properties – Preferred numbers, Limits, fits and tolerances. Types of loading, Direct, Bending and torsional stress equations – Impact and shock loading – calculation of principle stresses for various load combinations, eccentric loading Factor of Safety, Factor influencing the selection of Factor of Safety, Working stress, theories of failure – Design based on strength and stiffness

Design for variable loading: Fatigue load stress cycle, Fluctuating load, reversed and repeated load, Endurance limit, Endurance strength, Endurance limit, S-N curves, Modifying factors: Size, surface finish, Stress concentration factors, Goodman and Soderberg relationship, Stress due to combined loading

Unit 2

Design of Shaft, Coupling and Spring

Design of shaft based on strength, rigidity. Shaft subjected to combined twisting and bending moment, Shaft under fluctuating and combined loading, Design of Key and keyways

Rigid and flexible couplings

Springs: Design of springs for static and varying loads, Helical and leaf springs

Unit 3

Friction Drives

Clutches: types -single plate, multi plate, centrifugal and cone clutches.

Brakes-types, design of shoe (single and double), band, block, differential band brakes and internally expanding brakes, self energizing and self locking in brakes

Course Objectives

• Introduce basic concepts of design process
• Impart design principles involved in evaluating the critical design parameters of machine elements to satisfy functional and strength requirements
• Familiarize standard codes and practices to select materials and geometric parameters

Course Outcomes

• CO1: Select suitable materials for various machine elements
• CO2: Estimate allowable loads in machine elements using failure theories
• CO3: Analyze steady and variable stresses induced in machine elements for different applications
• CO4: Design shaft, keys, keyway, coupling, helical and leaf spring for specific applications
• CO5: Design friction drives for specific applications

CO – PO Mapping

Textbook(s)

• V.B. Bhandari, “Design of Machine Elements”, 4e, TMH, 2016

Reference(s)

• Richard G.Budynas, J.KeithNisbett, ” Shigley’s Mechanical Engineering Design”, 10e, TMH, 2015
• Hall, Holowenko, Laughlin, “Machine Design”, Special Indian Edition, TMH, 2008.
• Robert L.Norton, “Machine Design- An integrated Approach”, 5e., Pearson Education, New Delhi 2014

Evaluation Pattern