...
representative values of C’s are tabulated in Table 1 below.
Table 1. Values of C for various types of joints
Type of joint Value of C
Metal to metal joint with through bolt 0.00 – 0.10
Soft copper ...
The pressure causes external force of magnitude
c
pA
F
n
=
, where
n= number of equally spaced bolts on the bolt circle
= area of cross section of the cylinder
c
A
p = fluid pressure ... learn:
• Design of a bolted joint with fluctuating loading
• Design of welded joints with variable loading
1. Variable loading in mechanical joints:
Machine parts are often subjected to...
... What are the advantages of a belt drive?
A1. The advantages of a belt drive are that, it can absorb a good amount of
shock and vibration. It can take care of some degree of misalignment
between ... Kamalesh, Design ofMachine Elements,
Prentice Hall of India, New Delhi, 2003.
Version 2 ME , IIT Kharagpur
13.1.3 Nomenclature of Open Belt Drive
d
L
- Diameter of the larger ...
- Diameter of the larger pulley
d
S
– Diameter of the smaller pulley
α
L
- Angle of wrap of the larger pulley
α
S
– Angle of wrap of the smaller pulley
L
C- Center distance between...
...
The decision of the material to be used depends on the type of service.
No. of ply and Thickness
Ply is the number of layers as indicated earlier. Therefore, the number of ply is
decided ...
Coefficient of friction of the belt material
Coefficient of friction for a pair of belt material and pulley material is provided in
design data book.
13.2.4 Modification of Belt stress ... one.
When angle of wrap is less than 180
0
:
The maximum stress values are given for an angle of wrap is 180
ο
for both the
pulleys, ie, pulleys are of same diameter. Reduction of belt stress...
... end of this lesson, the students should be able to understand:
• Features of V-belt drives
• Nomenclature of V-belt, types of V-belt section and its power rating
• Selection procedure of ... angle of wrap of 3.00 radian (smaller pulley
herefore, incorporating the correction factors,
odified power rating of a belt (kW ) = Power rating of a belt (kW) x C
vw
x C
vl
), the angle of ... transmission falls in the lower side of
the given range.
Another restriction of choice of belt section arises from the view point of minimum
pulley diameter. If a belt of higher thickness (higher...
... hydrodynamic theory of lubrication
Petroff (1883) carried out extensive experimental investigation and showed the
dependence of friction on viscosity of lubricant, load and dimensions of the
journal ... Objectives:
At the end of this lesson, the students should be able to understand:
Types of bearings
Comparison of bearing friction characteristics
Basics of hydrodynamic theory of lubrication
Design ... of test of friction ( McKee brothers )
The Fig. 14.1.5 shows the results of test of friction by McKee brothers. Figure
shows a plot of variation of coefficient...
... Discuss ‘factor of safety ‘ in view of the reliability in machine design.
A.4: Reliability of a designed machine is concerned with the proper functioning
of the elements and the machine as a ... the end of this lesson, the students should have the knowledge of
• Basic concept of design in general.
• Concept ofmachine design and their types.
• Factors to be considered in machine ... stage of the design a designer must ensure that the machine may be
operated with ease. In many power operated machines it is simply a matter of
pressing a knob or switch to start the machine. ...
...
1) Design ofmachine elements by M.F.Spotts, Prentice hall of India,
1991.
2) Machine design-an integrated approach by Robert L. Norton,
Pearson Education Ltd.
3) A textbook ofmachine design ... and uses of some common non-ferrous metals.
• Types and uses of some non-metals.
• Important mechanical properties of materials.
1.2.1 Introduction
Choice of materials for a machine element ... fasteners, springs etc.
1.2.8 Summary of this Lesson
In this lesson the properties and uses of different types of metals and non-
metals, generally used in machine design, are discussed. Primarily...
... or
manufacture a product range. The range of operational speeds of a
machine or the range of powers of a typical machine may be also as per a
series of preferred numbers.
Version 2 ... other, the nature of fit is
dependent on the limits of tolerances and fundamental deviations of the mating
parts. The nature of assembly of two mating parts is defined by three types of fit
system, ... The nature of assembly of two mating parts is defined by three types of fit
system, Clearance Fit, Transition Fit and Interference Fit.
Clearance Fit: In this type of fit, the shaft of largest...
... that the state of stress
at a point can be given by six stress components only. It is important to
understand the implication of this state of stress at a point in the design of
machine elements ... cast iron machine parts of cross-sections shown in figure-2.1.7.2 are
subjected to bending moments. Which of the two sections can carry a
higher moment and determine the magnitude of the applied ... Design of members subjected to combined bending, torsion and axial loading.
• Buckling of beams.
2.1.1 Introduction
Stresses are developed in machine elements due to applied load and
machine...
...
At the end of this lesson, the student should be able to understand
• Elements of force system at a beam section.
• Superposition of axial and bending stresses.
• Transformation of plane stresses; ...
section X-X, Q the first moment of area, I the moment of inertia, t the width at
which transverse shear is calculated, J the polar moment of inertia and r the
radius of the circular cross-section. ... any
section a compressive stress of
π
2
4F
d
and a bending stress of
My
I
are
produced. Here d is the diameter of the circular bar, I the second moment of area
and the moment is
PL
2
...
... equation
The state of strain at a point can be completely described by the six strain
components and the strain components in their turns can be completely defined
by the displacement components u, ... strains
Consider an element AB of length δx ( figure-2.3.2.1). If displacement of end A is
u, that of end B is
u
u
x
∂
+δ
∂
x
. This gives an increase in length of (
u
u
x
∂
+δ
∂
x
-u) and
therefore ...
discussed.
2.3.9 Reference for Module-2
1) Mechanics of materials by E.P.Popov, Prentice hall of India, 1989.
2) Mechanics of materials by Ferdinand P. Boer, E. Russel Johnson, J.T
Dewolf,...
... Summary of this Lesson
Different types of loading and criterion for design ofmachine parts
subjected to static loading based on different failure theories have been
demonstrated. Development of ... to understand
• Types of loading on machine elements and allowable stresses.
• Concept of yielding and fracture.
• Different theories of failure.
• Construction of yield surfaces for failure ...
based on a particular failure criterion. Theories of failure are essentially a set of
failure criteria developed for the ease of design.
In machine design an element is said to have failed...
... change in length of 0.2 mm. Determine the
maximum stress developed in the bar. Take E= 200 GPa.
3.2.4.1F
A.1:
Total change in length of the bar is made up of three components ...
3.2.1.4F- Variation of theoretical stress concentration factor with r/d of a stepped
shaft for different values of D/d subjected to uni-axial loading (Ref.[2]). ...
figure-3.2.3.1
‘a’ is the radius of the hole
and at r=b, b>>a the stresses are not affected by the presence of the hole.
Version 2 ME, IIT Kharagpur
3.2.2 Methods of reducing stress concentration...
...
1) Design ofmachine elements by M.F.Spotts, Prentice hall of India,1991.
2) Machine design-an integrated approach by Robert L. Norton, Pearson
Education Ltd, 2001.
3) A textbook ofmachine ... However, in the presence of notches and cracks
determination of total strain is difficult.
3.4.1.2F- Plots of strain amplitude vs number of stress reversals for
failure. ... students should be able to understand
• Design ofcomponents subjected to low cycle fatigue; concept and necessary
formulations.
• Design ofcomponents subjected to high cycle fatigue loading...
... applications.
4.1.1 Introduction: Types of fasteners
A machine or a structure is made of a large number of parts and they need be
joined suitably for the machine to operate satisfactorily. Parts ... the end of this lesson, the students should have the knowledge of
• Fasteners and their types: permanent and detachable fasteners.
• Different types of pin joints.
• Different types of keys ...
4.1.2.3F- Typical use of a split pin (Ref.[6]).
4.1.3 Keys
Steel keys are widely used in securing machine parts such as gears and pulleys.
There is a large variety ofmachine keys and they...