Table Of ContentTo my daughters, Helen and Sarah
Mechanical Engineer's
Data Handbook
J. Carvill
■ J U T T E R W O R TH
E I N E M A N N
Butterworth-Heinemann Ltd
Linacre House, Jordan Hill, Oxford OX2 8DP
Φ PART OF REED INTERNATIONAL BOOKS
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TOKYO TORONTO WELLINGTON
First published 1993
© Butterworth-Heinemann 1993
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British Library Cataloguing in Publication Data
Carvill, James
Mechanical Engineer's Data Handbook
I. Title
621
ISBN 0 7506 1014 X
Library of Congress Cataloguing in Publication Data
Carvill, James.
Mechanical engineer's data handbook/J. Carvill.
p. cm.
Includes index.
ISBN 0 7506 1014 X
1. Mechanical engineering - Handbooks, manuals, etc. I. Title.
TJ151.C36
621-dc20 92-19069
CIP
Typeset by Vision Typesetting, Manchester
Printed and bound in Great Britain by Bath Press, Bath, Avon
Preface
There are several good mechanical engineering data books on the market but these tend to be very bulky and
expensive, and are usually only available in libraries as reference books.
The Mechnical Engineer's Data Handbook has been compiled with the express intention of providing a
compact but comprehensive source of information of particular value to the engineer whether in the design office,
drawing office, research and development department or on site. It should also prove to be of use to production,
chemical, mining, mineral, electrical and building services engineers, and lecturers and students in universities,
polytechnics and colleges. Although intended as a personal handbook it should also find its way into the libraries
of engineering establishments and teaching institutions.
The Mechanical Engineer's Data Handbook covers the main disciplines of mechanical engineering and
incorporates basic principles, formulae for easy substitution, tables of physical properties and much descriptive
matter backed by numerous illustrations. It also contains a comprehensive glossary of technical terms and a full
index for easy cross-reference.
I would like to thank my colleagues at the University of Northumbria, at Newcastle, for their constructive
suggestions and useful criticisms, and my wife Anne for her assistance and patience in helping me to prepare this
book.
J. Carvill
Symbols used in text
a Acceleration j Operator y/~—1
A Area J Polar second moment of area
stf Anergy k Radius of gyration; coefficient of thermal
b Breadth conductivity; pipe roughness
b.p. Boiling point K Bulk modulus; stress concentration
B Breadth, flux density factor
c Clearance, depth of cut; specific heat KE Kinetic energy
capacity K Wahl factor for spring
w
C Couple; Spring coil index; velocity I Length
(thermodynamics); heat capacity L Length
Q Drag coefficient, discharge coefficient m Mass; mass per unit length; module of
COP Coefficient of performance gear
Cp Specific heat at constant pressure m Mass flow rate
c Specific heat at constant volume; velocity m.p. Melting point
v
coefficient M Mass; moment; bending moment;
cv Calorific value molecular weight
d Depth; depth of cut; diameter; MA Mechanical advantage
deceleration n Index of expansion; index; number of;
D Depth; diameter; flexural rigidity rotational speed
e Strain; coefficient of restitution; N Rotational speed; number of
emissivity N Specific speed
s
E Young's Modulus; energy; luminance; N» Nusselt number
effort P Pressure; pitch
EL Elastic limit; endurance limit P Power; force; perimeter
ELONG°/c > Percentage elongation pr Prandtl number
S Exergy PE Potential energy
f Frequency; friction factor; feed PS Proof stress
F Force; luminous flux Ö Heat quantity; volume flow rate; metal
Fg Strain gauge factor removal rate
FL Fatigue limit r Radius; pressure or volume ratio
FS Factor of safety R Radius; electric resistance; reaction,
g Acceleration due to gravity thermal resistance; gas constant
G Shear modulus; Gravitational constant Re Reynolds number
G Grashof number RE Refrigeration effect
r
h Height; thickness; specific enthalpy; Universal gas constant
*o
shear, heat transfer coefficient s Specific entropy; stiffness
h.t.c. Heat transfer coefficient S Entropy, shear force, thermoelectric
H Enthalpy; height, magnetic field strength sensitivity
i Slope; operator ^J — 1 SE Strain energy
I Moment of inertia; Second moment of s« Stanton number
area; luminous intensity, electric current t Temperature; thickness; time
X MECHANICAL ENGINEER'S DATA HANDBOOK
T Time; temperature; torque; tension; a Angle; coefficient of linear expansion;
thrust; number of gear teeth angular acceleration; thermal diffusivity;
TS Tensile strength Resistance temperature coefficient
u Velocity; specific strain energy; specific ß Angle; coefficient of superficial expansion
internal energy y Angle; coefficient of volumetric
u Internal energy; strain energy; overall expansion; ratio of specific heats
heat transfer coefficient δ Angle
UTS Ultimate tensile stress ε Permittivity
V Velocity; specific volume Ά Efficiency
V Velocity; voltage, volume Θ Angle; temperature
VR Velocity ratio λ Wavelength
w Weight; weight per unit length μ Absolute viscosity; coefficient of friction
W Weight; load; work; power (watts) V Poisson's ratio; kinematic viscosity
X Distance (along beam); dryness fraction Ρ Density; resistivity; velocity ratio
X Parameter (fluid machines) Ρο Resistivity
y Deflection σ Stress; Stefan-Boltzmann constant
YP Yield point τ Shear stress
YS Yield stress Φ Friction angle; phase angle; shear strain;
z Bending modulus; impedance; number of pressure angle of gear tooth
Polar modulus ω Angular velocity
ZP
Strengths of materials
LI Types of stress
Engineering design involves the correct determination dimensional stress is dealt with, although many cases
of the sizes of components to withstand the maximum of three-dimensional stress combinations occur. The
stress due to combinations ofdirect, bending and shear theory is applied to the special case of shafts under
loads. The following deals with the different types of both torsion and bending,
stress and their combinations. Only the case of two-
U
I.I.I Direct, shear and bending stress B - 6ß B
Tensile and compressive stress (direct stresses)
ΡΤΓΪΞ3 fc
load P
Stress σ =
area A
extension x
Strain e =
original length L Shear stress
Stress σ ^ , , ^ _ ^ PL
— = - = Yτ oungs mod uΛlus, E. Thus E = —
Strain e Ax Shear stress τ = —
A
p 1 P Shear strain φ = —, where G = Shear modulus.
μ-
φ=
τ
GJ-L·
h-
Ax
Note: A is parallel to the direction of P.
Poisson's ratio
strain in direction of load
Poisson's ratio v =
strain at right angles to load
δΒ/Β_ββ
JL/L~7
L
Note: ife is positive, e is negative.
L B
2 MECHANICAL ENGINEER'S DATA HANDBOOK
Bending stress
My
Bending stress er =
where:
M = bending moment
/ = second moment of area of section
y = distance from centroid to the point considered
My
Maximum stress a = - m
m I
where y = maximum value of y for tensile and com-
m
pressive stress.
El Relationship between elastic constants
Radius of curvature R = —
M
E E 9GK
Bending modulus Z = I/y and a = M/Z K = ———^ G = — -; E =
m m 3(1-2v) 2(l + v)' (G + 3X)
Compound stress
For normal stresses σ and a with shear stress τ:
χ y
Maximum principal stress σ = (c + a)/2 + T
{ x y max
Minimum principal stress σ = (σ + σ)/2 — T
2 χ γ max
NA = neutral axis where: maximum shear stress TmaY = " — + τ'
Combined bending and direct stresses
a = p/A ± M/Z where Z = —
c
Z,A
Hydrostatic (three-dimensional) stress
Volumetric strain e = —
y
Bulk modulus K = p/e Combined bending and torsion
v
where p = pressure and V= volume.
For solid and hollow circular shafts the following can
be derived from the theory for two-dimensional (Com
pound) stress. If the shaft is subject to bending moment
STRENGTHS OF MATERIALS 3
M and torque Γ, the maximum direct and shear Stress due to a 'suddenly applied9 load (h = 0)
stresses, a and i are equal to those produced by
m m
'equivalent' moments M and T where
e e
t = TJZ and o = MJZ
m p m Stress due to a mass M moving at velocity v
where Z = polar modulus
p
ImE
T = ^/Μ2 + Τ2 and M = {M+ TJ/2
e e
nD3 π (D4-d4)
Z = —— (solid shaft) or — (hollow shaft)
1
nD3 π (D*-dA)
Z = -^- (solid shaft) or — (hollow shaft)
p
16 16 D
See section 1.1.7.
h I
.X
X"
.
1. 1.3 Compound bar in tension
1. 1.2 Impact stress
A compound bar is one composed of two or more bars
In many components the load may be suddenly
of different materials rigidly joined. The stress when
applied to give stresses much higher than the steady
loaded depends on the cross-sectional areas (Α and
stress. An example of stress due to a falling mass is Λ
A) areas and Young's moduli (£ and E ) of the
given. h a h
components.
Maximum tensile stress in bar
Stresses
o = cl\+J\H2h/xJ]
m
where:
A + (EJE)A*
a = steady stress = mg/A a a
s
x = steady extension = mgL/AE F
s
h = height fallen by mass m. = A + (EJE)A
b h a
4 MECHANICAL ENGINEER'S DATA HANDBOOK
Strains Failure may be due to any one of the following
stresses.
ea = ffa/£a; eb = ob/Eb (note that ea = eb) (1) Tensile in rod a = 4P/nD2
t
Έ3-
V///////////A p-*-\
k\\\\\\\\\^^
W//////////A (2) Tensile in eye at = P/(D0-D)b
1. 1.4 Stresses in knuckle joint
The knuckle joint is a good example of the application
of simple stress calculations. The various stresses
which occur are given.
Symbols used:
P = load
<rt = tensile stress (3) Shear in eye T = P/(D0-Dp)b
a = bending stress
b
o = crushing stress
c
τ = shear stress
D = rod diameter
D = pin diameter
p
D = eye outer diameter
0
a = thickness of the fork
b = the thickness of the eye
approx
(4) Tensile in fork a = P/(D-D)2a
t 0 p
a a
c^c
L·
(5) Shear in fork T = P/(D-D)2a
0 p
XI
"^
