Course Detail

16 Weeks

Design of Machine Members - I

Course Information


Design of Machine Members-I

This Course is about the creation of new and better machines and improving the existing ones. The process of design is a long and time consuming one. From the study of existing ideas, a new idea has to be conceived. The idea is then studied keeping in mind its commercial success and given shape and form in the form of drawings.


Knowledge of Mathematics, Engineering Mechanics, Strength of Materials, Theory of Machines, Workshop Processes and Engineering Drawing.

Course Objectives:

Upon completion of this course, students will be able to do the following:

•The student shall gain appreciation and understanding of the design function in mechanical engineering, the steps involved in designing and the relation of design activity with manufacturing activity
•Selection of proper materials to different machine elements based on their physical and mechanical properties.
•Learn and understanding of the different types of failure modes and criteria.
•Procedure for the different machine elements such as fasteners, shafts, couplings, keys, axially loaded joints etc.

Course Outcomes:

After completing this course the candidate should be able to:

•Apply the design procedure to engineering problems, including the consideration of technical and manufacturing constraints.
•Select suitable materials and significance of tolerances and fits in critical design applications.
•Utilize design data hand book and design the elements for strength, stiffness and fatigue.
•Identify the loads, the machine members subjected and calculate static and dynamic stresses to ensure safe design.


Unit 1

INTRODUCTION:: General considerations in the design of Engineering Materials and their properties – selection –Manufacturing consideration in design, tolerances and fits –BIS codes of steels.

STRESSES IN MACHINE MEMBERS: Simple stresses – combined stresses – torsional and bending stresses – impact stresses – stress strain relation – various theories of failure – factor of safety – design for strength and rigidity – preferred numbers. the concept of stiffness in tension, bending, torsion and combined situations – static strength design based on fracture toughness.

Unit 2

STRENGTH OF MACHINE ELEMENTS: Stress concentration – theoretical stress concentration factor – fatigue stress concentration factor notch sensitivity – design for fluctuating stresses – endurance limit – estimation of endurance strength – Goodman’s line – Soderberg’s line – modified Goodman’s line.

Unit 3

Riveted and welded joints – design of joints with initial stresses – eccentric loading. Bolted joints – design of bolts with pre-stresses – design of joints under eccentric loading – locking devices – both of uniform strength, different seals.

Unit 4

KEYS, COTTERS AND KNUCKLE JOINTS: Design of keys-stresses in keys-cotter joints-spigot and socket, sleeve and cotter, jib and cotter joints- knuckle joints.

SHAFTS:Design of solid and hollow shafts for strength and rigidity – design of shafts for combined bending and axial loads – shaft sizes – BIS code. Use of internal and external circlips, gaskets and seals (stationary & rotary).

Unit 5

SHAFT COUPLING: Rigid couplings – muff, split muff and flange couplings, flexible couplings – flange coupling (modified).

Unit 6

MECHANICAL SPRINGS: Stresses and deflections of helical springs – extension -compression springs – springs for fatigue loading, energy storage capacity – helical torsion springs – co-axial springs, leaf springs..