DESIGN OF MACHINE ELEMENTS QUESTION BANK

R.M.K COLLEGE OF ENGINEERING
AND TECHNOLOGY
RSM NAGAR, PUDUVOYAL-601206
DEPARTMENT OF MECHANICAL ENGINEERING
ME6503 – DESIGN OF MACHINE ELEMENTS
V SEM MECHANICAL ENGINEERING
Regulation 2013
QUESTION BANK
PREPARED BY
R.ASHOK KUMAR M.E (Ph.D)

R.M.K COLLEGE OF ENGG AND TECH / AQ / R2013/ ME6503 / V / MECH / JUNE 2017 – NOV 2017
ME6503 – DESIGN OF MACHINE ELEMENTS QUESTION BANK by ASHOK KUMAR.R (AP / Mech) 2
ME6503 DESIGN OF MACHINE ELEMENTS
UNIT – I STEADY STRESSES AND VARIABLE STRESSES IN MACHINE
MEMBERS 10
Introduction to the design process - factors influencing machine design, selection of materials based
on mechanical properties - Preferred numbers, fits and tolerances – Direct, Bending and torsional
stress equations – Impact and shock loading – calculation of principle stresses for various load
combinations, eccentric loading – curved beams – crane hook and „C‟ frame- Factor of safety -
theories of failure – Design based on strength and stiffness – stress concentration – Design for variable
loading
UNIT – II SHAFTS AND COUPLINGS 8
Design of solid and hollow shafts based on strength, rigidity and critical speed – Keys, keyways and
splines - Rigid and flexible couplings.
UNIT – III TEMPORARY AND PERMANENT JOINTS 9
Threaded fasteners - Bolted joints including eccentric loading, Knuckle joints, Cotter joints – Welded
joints, riveted joints for structures - theory of bonded joints.
UNIT – IV ENERGY STORING ELEMENTS AND ENGINE COMPONENTS 9
Various types of springs, optimization of helical springs - rubber springs - Flywheels considering
stresses in rims and arms for engines and punching machines- Connecting Rods and crank shafts.
UNIT – V BEARINGS 9
Sliding contact and rolling contact bearings - Hydrodynamic journal bearings, Somerfield Number,
Raimondi and Boyd graphs, -- Selection of Rolling Contact bearings. TOTAL: 45 PERIODS
TEXT BOOK:
 Bhandari V, “Design of Machine Elements”, 3rd Edition, Tata McGraw-Hill Book Co, 2010.
 Joseph Shigley, Charles Mischke, Richard Budynas and Keith Nisbett “Mechanical
Engineering Design”, 8th Edition, Tata McGraw-Hill, 2008.
REFERENCES:
 Sundararajamoorthy T. V. Shanmugam .N, “Machine Design”, Anuradha Publications, Chennai, 2003.
 Robert C. Juvinall and Kurt M. Marshek, “Fundamentals of Machine Design”, 4th Edition, Wiley,
2005
 Alfred Hall, Halowenko, A and Laughlin, H., “Machine Design”, Tata McGraw-Hill Book
Co.(Schaum‟s Outline), 2010
 Bernard Hamrock, Steven Schmid,Bo Jacobson, “Fundamentals of Machine Elements”,2nd Edition,
Tata McGraw-Hill Book Co., 2006.
 Orthwein W, “Machine Component Design”, Jaico Publishing Co, 2003.
 Ansel Ugural, “Mechanical Design – An Integral Approach", 1st Edition, Tata McGraw-Hill Book Co,
2003.
 Merhyle F. Spotts, Terry E. Shoup and Lee E. Hornberger, “Design of Machine Elements” 8th Edition,
Printice Hall, 2003.

UNIT – I – STEADY STRESSES AND VARIABLE STRESSES IN
MACHINE ELEMENTS
PART - A
1.1) Define CAD.
1.2) What are the advantages of CAD?
1.3) What are the factors to be considered in the selection of materials for a machine
element?
1.4) How the machine design may be classified? [AU, Nov / Dec – 2016]
1.5) What is an adaptive design? [AU, Apr / May – 2015, May / Jun – 2016]
1.6) What is adaptive design? Where it is used? Give examples.
[AU, Nov / Dec – 2012]
1.7) How are materials classified?
1.8) What are the common materials used in mechanical engineering design?
[AU, Nov / Dec – 2015]
1.9) What are the mechanical properties to be considered in selecting a material for
engineering applications?
1.10) What are the mechanical properties of metals? List any four mechanical
prosperities. [AU, May / Jun - 2012]
1.11) What is meant by interchangeability?
1.12) What are the steps in machine design process? [AU, Apr / May – 2010]
1.13) How will you account for stress concentration in design of the machine parts ?
[AU, Apr / May – 2010]
1.14) What do you mean by Optimum design? [AU, Nov / Dec –2011]
1.15) What are the methods to reduce stress concentration? [AU, Nov / Dec –2008]
1.16) Define nominal, basic and actual size.
1.17) What is meant by tolerance?
1.18) Define limits of size.
1.19) Define limits and fits. [AU, Apr / May – 2015, May / Jun – 2016]
1.20) Define fits, clearance and interference.
1.21) What are the types of fits? [AU, Nov / Dec– 2008]
1.22) Write short notes on clearance fit and interference fit.

1.23) Explain transition fit.
1.24) What are unilateral and bilateral tolerances?
[AU, May / Jun - 2013, Nov / Dec – 2016]
1.25) Using the table for tolerances, find the types of fit, maximum and minimum
clearance of interference for 150 G7 – e8 combination.
1.26) The fit between a hole and a shaft is defined by  70 H9F7. Find the allowance.
1.27) What is hole basis system?
1.28) What is shaft basis system?
1.29) Define preferred numbers.
1.30) What is meant by standardization?
1.31) Mention some standard codes of specification of steels. [AU, Nov / Dec– 2008]
1.32) Define load. What are the different types of loads that can act on machine
components?
1.33) What are the factors that govern selection of materials while designing a machine
component? [AU, Nov / Dec– 2010]
1.34) What is steady and variable load?
1.35) What is impact load? [AU, Nov / Dec – 2015]
1.36) What is an impact load? Give example. [AU, May / Jun - 2012]
1.37) What is meant by shock and impact load?
1.38) What are the methods used to improve fatigue strength? [AU, Nov / Dec –2013]
1.39) List at least two methods to improve the fatigue strength. [AU, Nov / Dec –2014]
1.40) Define stress and strain.
1.41) Define Poisson’s ratio. [AU, Apr / May – 2011]
1.42) Explain the normal stress theory and its limitations [AU, Apr / May – 2010]
1.43) Which theory of failure is suitable for the design of brittle materials?
[AU, Nov / Dec – 2015]
1.44) Explain the different types of stresses.
1.45) What is meant by double shear? Give an example.
1.46) Define resilience [AU, Nov / Dec –2009, April / May – 2017]
1.47) Define modulus of resilience and proof resilience. [AU, April / May – 2017]
1.48) What in meant by modulus of rigidity?
1.49) Explain factor of safety. [AU, Apr / May – 2010]

1.50) Define factor of safety. [AU, Nov / Dec –2012, 2015]
1.51) List the important factors that influence the magnitude of factor of safety.
[AU, Nov / Dec –2011]
1.52) What is an S-N curve? [AU, Nov / Dec – 2016]
1.53) Explain stress - strain diagram with an example.
1.54) What is the yield point of the material?
1.55) The material of a shaft is changed from C40 steel to alloy steel to increase the
rigidity. Give your comment. [AU, April / May – 2017]
1.56) Define ultimate and breaking stress.
1.57) Explain working stresses.
1.58) Differentiate the stress distribution in a bar subjected to an axial force and beam
subjected to bending [AU, Apr / May – 2010]
1.59) What is factor of safety for brittle materials? [AU, Apr / May – 2011]
1.60) Discuss the factors affecting the selection of factor of safety.
1.61) Define Poisson's ratio and bulk modulus.
1.62) Give the relation between bulk modulus and Young's modulus.
1.63) Give the relation between Young's modulus and modulus of rigidity.
1.64) Calculate the force required to punch a circular blank of 60 mm diameter in a plate
of 5 mm thick. The ultimate shear stress of the plate is 350 N/mm2
.
1.65) Determine the force required to punch a hole of 20mm diameter in a 5mm thick
plate with ultimate shear strength of 250 MPa? [AU, Nov / Dec –2014]
1.66) A mild steel bar of 12mm diameter is subjected to an axial load of 50 KN in
tension. Find the magnitude of the induced stress.
1.67) A M.S. bar of diameter 12 mm and length 1 m is subjected to an axial load of 50
KN in tension and modulus of elasticity is 2 x 105MPa. Find the elongation of the
bar.
1.68) Steel flat 10 mm wide and 12 mm thick is bent into a circular arc of radius 12 m.
Find the maximum intensity of stress induced in the cross section.
1.69) How is the allowable stress estimated in ductile and brittle materials?
1.70) Define the term principal planes and principal stress
1.71) State the various theories of failure.

1.72) What are the various theories of failure?
[AU, May / Jun - 2013, Nov / Dec – 2016]
1.73) What is the maximum principal strain theory (Saint Vennant's theory)?
[AU, Nov / Dec – 2009]
1.74) State the maximum strain energy theory (Haigh's theory)
1.75) State the difference between straight beams and curved beams.
[AU, Nov / Dec –2012]
1.76) Why nonsymmetrical I and T sections are preferred in design of curved beams?
[AU, April / May – 2017]
1.77) What is eccentric loading?
1.78) Define stress concentration. [AU, May / Jun – 2012, 2016]
1.79) What is meant by stress concentration?
[AU, May / Jun - 2009, Nov / Dec –2011]
1.80) Give one method of reducing stress concentration in key slots.
[AU, May / Jun - 2012]
1.81) What are the sources of stress concentration in machine elements?
1.82) Define stress concentration factor.
1.83) Define stress concentration and stress concentration factor.
[AU, May / Jun – 2014]
1.84) How to avoid stress concentration? [AU, Nov / Dec –2012]
1.85) What are the methods of reducing stress concentration?
[AU, May / Jun - 2009]
1.86) What are the factors to be considered while designing machine parts to avoid
fatigue failure?
1.87) Define fatigue stress concentration factor.
1.88) Define (a) stiffness and (b) resilience [AU, May / Jun - 2009]
1.89) Describe the material properties of hardness, stiffness and resilience.
[AU, Nov / Dec –2013, May / Jun – 2016]
1.90) Differentiate between hardness and toughness of materials.
[AU, May / Jun – 2014]
1.91) What are the types and modes of fracture?
1.92) Explain soderberg and Goodman lines in details.

1.93) What is Geber theory [AU, Nov / Dec – 2009]
1.94) Write Soderberg equation for a machine component subjected to
(a)Combination of mean and variable torques
(b) Combination of mean and variable bending moments [AU, Nov / Dec – 2010]
PART –B
1.95) Discuss in detail about the factors influencing machine design.
[AU, May / Jun - 2012]
1.96) What are the factors influencing machine design? Explain it.
[AU, May / Jun – 2014]
1.97) Explain various phases in Design using a flow diagram and enumerate the factors
influencing the machine design. [AU, May / Jun - 2013]
1.98) What is factor of safety? List the factors to be considered while deciding the factor
of safety. [AU, May / Jun – 2014]
1.99) Write short notes on preferred numbers, fits and types of fits.
[AU, May / Jun - 2012]
1.100) What is meant by hole basis system and shaft basis system? Which one is
preferred and why? [AU, May / Jun - 2013]
1.101) Explain the maximum normal stress theory of failure (Rankine's theory)
1.102) Explain the maximum shear theory of failure (Guest's theory)
1.103) Explain distortion energy theory of failure (Hencky and Von Mises theory)
1.104) What is the difference between Gerber curve and soderberg and Goodman lines?
[AU, May / Jun - 2013]
1.105) Explain notch sensitivity. What are the factors that affect notch sensitivity?
1.106) Explain in detail the maximum shear stress theory [AU, Nov / Dec – 2009]
1.107) Explain soderberg and Goodman lines in details. [AU, Nov / Dec – 2009]
1.108) Discuss in detail about CAD and optimum design. State their relevance in
designing mechanical elements. [AU, Nov / Dec – 2008]
1.109) Write short notes on the following: [AU, May / Jun – 2014]
 Interchangeability
 Tolerance
 Allowance

1.110) Define Stress concentration. Give some methods of reducing stress
concentration. [AU, Nov / Dec –2011]
1.111) The dimensions of mating parts, according to basic hole system are given as
follows:
Hole: 25mm Shaft: 24.97mm
25.02mm 24.95mm
Find the hole tolerance, shaft tolerance and allowance.
1.112) The following results were obtained in a tensile test on a mild steel specimen of
original diameter of 20 mm and guage length 40 mm. At the limit of proportionality,
the load was 80000 N and extension is 0.048 mm. The specimen yielded at a load of
85000 N and the maximum load was 150000 N. When two parts are fitted together
after being broken, the guage length was found to be 55.6 mm and the diameter at
neck was 15.8 mm. Calculate the Young’s modulus, stress at the limit of
proportionality, yield stress, ultimate stress, percentage elongation and reduction and
working stress. Take factor of safety = 2
1.113) Consider two aluminum rods and one steel rod combined as one unit which
supports a weight of 1000 kg. If the area of cross section of aluminum and steel rods
is 2 cm2
each and strains are equal, find the stresses acting on aluminum and steel
rods.
2626
/10x1.2/10x7.0 cmkgfEcmkgfE steelAl 
1.114) An unknown weights falls through 10mm onto a collar which is rigidly attached
to the lower end of a vertical bar 3 m long and 600 mm2
cross section. The maximum
instantaneous extension is 2mm. What is the corresponding stress and the value of
the weight? Take E = 200 kN/mm2
. [AU, Nov / Dec –2014, 2015, 2016]
1.115) A flat bar 32 mm wide and 12 mm thick is loaded by a steady tensile load of 85
kN. The material is mild steel with yield point stress of 315 N/mm2
. Find the factor
of safety based on the yield point. [AU, Nov / Dec – 2008]
1.116) A flat plate of width 60 mm has a central hole of 10 mm diameter. If the plate is
subjected to an axial tensile load of 10 kN, determine the thickness of the plate.
Assume yield point stress 300 MPa and factor of safety as 2.5.
[AU, Nov / Dec – 2008]

1.117) A shaft is transmitting 100 KW at 160 rpm. Find the suitable diameter of the
shaft if the maximum torque transmitted exceeds the mean by 25%. Take the
maximum allowable shear stress as 70 MPa.
1.118) A cast iron pulley transmits 10kW at 400rpm. The diameter of the pulley is 1.2m
and it has four straight arms of elliptical cross section in which the major axis is
twice of the minor axis. Determine the dimension of the arm if the allowable bending
stress is 15MPa. [AU, May / Jun - 2009]
1.119) A shaft is supported in bearings, the distance between their centers being 1 m. It
carries a pulley in the centre and it weighs 1 KN. Find the diameter of the shaft, if
the permissible bending stress for the shaft material is 40 N/mm
2
.
1.120) Determine the diameter of circular rod made of ductile material with endurance
limit is 265MPa and tensile yield strength of 350MPa. The member is subjected to a
varying axial load form – 300kN to 700kN and has a stress concentration factor is
1.8. The factor of safety as 2. [AU, May / Jun - 2009]
1.121) Two rods made of plain carbon steel 40C8 (Syt= 380 N/mm2
) are connected by
means of cotter joint. The diameter of each rod is 50mm and the cotter is made of
steel plate of 15mm thickness. Calculate the dimension of the socket end making the
following assumptions. (i) the yield strength in compression is twice of the tensile
yield strength and (ii) the yield strength in shear is 50% of the tensile yield strength.
Factor of safety is 6. [AU, Nov / Dec – 2009]
1.122) It is desired to bend a strip of 6 mm thick and 20 mm wide of spring steel into a
loop with the end overlapping and riveted. Find the minimum radius of the loop if
the stresses due to bending are limited to 100 MPa. Also determine the bending
moment required to bend the strip. Take Young’s modulus .10x1.2 5
MPaE 
1.123) A rod of linkage mechanism made up of steel 40Crl (Sut = 550N/mm2
) is
subjected to completely reversed axial load of 100kN. The rod is machined on the
lathe and expected reliability is 95%. There is no stress concentration. Determine the
diameter of the rod using a factor of safety of 2 for an infinite life condition.
[AU, Nov / Dec – 2009]
1.124) A shaft transmits 20 KW power and rotates at 500 rpm. The material of shaft is
50 C4 and the factor of safety is 2.

Determine the diameter of the shaft on the basis of its shear strength
Determine the diameter of shaft on the basis of its torsional rigidity, if the
permissible angle of twist is 30
per meter length and the modulus of rigidity
of the shaft material is 79300 N/mm2
. [AU, May / June – 2007]
1.125) Design a suitable diameter for a circular shaft required to transmit 90 KW at 120
rpm. The shear stress for the shaft is not to exceed 70 N/mm2
and the maximum
torque exceeds the mean by 40 %.
1.126) The shaft of an overhang crank is subjected to a force F of 2kN as shown in
figure. The shaft is made of 30Mn2 steel having an allowable shear strength equal to
100N/mm2
. Determine the diameter of the shaft.
[AU, Apr / May – 2015, May / Jun – 2016]
1.127) A weight W falls 10mm on a collar rigidity attached to the lower end of vertical
part 6m long 400mm2
in cross section. The maximum instantaneous extension is
found to be 2mm. Take Young’s modulus 2 * 105
N/mm2
. Find the value W and
impact stress induced
1.128) A bolt is subjected to a direct tensile load of 25kN and shear load of 15kN.
Considering various theories of failure, determine the suitable size of bolt if the yield
stress in tension is 250N/mm2
. Take FOS as 2 and Poisson’s ratio as 0.3
[AU, Nov / Dec – 2008]
1.129) An I-section beam of depth 250 mm is supported at two points 4 m apart. It is
loaded by a weight of 4 KN falling through a height h and striking the beam at mid
span. The moment of inertia of the section is 8 x 107
mm4
; E = 210 KN/ mm2
.
Determine h if the stress is 120 N/mm2
.

1.130) A man weighing 60 kg jumps from a height of 50 cm on a diving board of
rectangular cross - section having 30 cm width and 2 m long. If the maximum induced
stress is limited to 400 kg/cm2 and the modulus of elasticity of the board is 1 x
105kg/cm2, find the thickness of the diving board.
1.131) A cantilever beam of span 800mm carries a uniformly distributed load of
12kN/m. the yield value of material of cantilever is 400MPa. Factor of safety is 2.5
find the economical section of cantilever among (i) circular cross section of diameter
‘d’ (ii)rectangular cross section of depth ‘d’ and width ‘w’ d/w= 2.5 (iii) ‘I’ section
of total depth 7t width 5t where ‘t’ is thickness. Find the dimension and cross
sectional area of the economic section [AU, Apr / May – 2010]
1.132) A vertical pillar of 50 mm diameter is subjected to a vertical load of 1 kN acting
eccentrically at a distance of 30 mm from the axis. Calculate the maximum stress in
the pillar and locate it.
1.133) A hollow circular column of external diameter 250 mill and internal diameter
200 mm carries a projecting bracket on which a load of 20 kN rests, as shown in Fig.
The centre of the load from the centre of the column is 500 mm. Find the stresses at
the sides of the column. All dimensions in mm. [AU, Nov / Dec – 2016]

1.134) A shaft of diameter 40 mm is used to transmit the power of 30 KW at 710 rpm
and is supported in bearings 500 mm apart. A load of 10 KN is concentrated at the
centre of shaft vertically. Calculate the maximum principle stress and shear stress.
1.135) A hollow shaft is required to transmit 600 kW at 110 rpm, the maximum torque
being 20% greater than the mean. The shear stress is not to exceed 63 Mpa and twist
in a length of 3 meter not to exceed 1.4 degrees. Find the external diameter of the
shaft, if the internal diameter to the external diameter is 3/8. Take modulus of rigidity
as 84 Gpa. [AU, Apr / May 2011]
1.136) Determine the diameter of a steel bar, which is of ductile nature subjected to an
axial tensile of 60kN and torsional moment of 1600N-m. Use the factor of safety of
2.5, E= 200GPa [AU, Apr / May – 2010]
1.137) A shaft as shown in figure is subjected to a bending load of 3kN, pure torque of
1000 N-m and an axial pulling force of 15kN. Calculate the stress at A and B
[AU, Apr / May – 2010, May / Jun – 2016]

1.138) A cantilever beam made of cold drawn carbon steel of circular cross section as
shown in fig ., is subjected to a load which varies from –F to 3 F. Determine the
maximum load that this member can withstand for an indefinite life using a factor of
safety as 2. The theoretical stress concentration factor is 1.42 and the notch
sensitivity is 0.9.
Assume the following values:
Ultimate stress =550 Mpa
Yield stress = 470 Mpa
Endurance limit = 275 Mpa
Size factor = 0.85
Surface finish factor = 0.89. [AU, Apr / May – 2011]
1.139) A simply supported beam has concentrated load at the centre which fluctuates
a value from P to 4P. The span of the beam is 500 mm and its cross section is circular
with a diameter of 60 mm. Beam material is cold drawn 0.2% carbon steel. Calculate
the maximum permissible value of P for a factor of safety of 1.3. Beam surface is
ground [AU, Nov / Dec – 2010]
1.140) A wall crane with a pin - joint tie rod is as shown in Fig. The crane hook is to
take a maximum load 35 kN, when the load is at a distance of 2 m from the wall. The
tie rod and pin are made of steel FeG 250 (Syt = 250 N/mm2
) and the factor of safety
is 5. Calculate the diameter of the tie rod and the pin. [AU, April / May – 2017]

1.141) The C frame of 100kN capacity press is shown in fig. the material of the frame
is grey cast iron an d the factor of safety is 3 determine the dimensions of the frame
[AU, Apr / May – 2010]
1.142) The frame of a punch press is shown in fig. Find the stresses at the Inner and
outer surface at section X-X of the frame, if W = 5000 N. [AU, May / Jun – 2014]

1.143) A bracket as shown in figure is bolted to the frame - work of a machine which
carries a load P. The cross - section of the bracket is rectangle with 30 mm wide and
60 mm deep. If the maximum stress is limited to 30 N/mm2
, find the value of P.
[AU, Apr / May – 2011]
1.144) A mild steel bracket is shown in figure. It is subjected to a pull of 6000 N acting
at 450
to the horizontal axis. The bracket has a rectangular section whose depth is
twice the thickness. Find the cross sectional dimensions of the bracket if the
permissible stress in the material is 60MPa [AU, Nov / Dec – 2012]
1.145) A cast-iron link, as shown in figure, is to carry a load of 20 kN. If the tensile and
compressive stresses in the link are not to exceed 25 MPa and 80 MPa respectively,
obtain the dimensions of the cross- section of the Link at the middle of its length.
[AU, Nov / Dec –2013]

1.146) A bell crank is driving a condenser air pump. A force of 8000 N is acting on the
pin A. The lever is a steel forging turning on a pin as the fulcrum. Design the bell
crank lever assuming the following data: Allowable stress in tension 80 N/mm2
and
allowable stress in shear 62 N/mm2
for the pin. [AU, April / May – 2017]
1.147) A mild steel bracket is shown in figure. It is subjected to a pull of 5000 N acting
at 450
to the horizontal axis. The bracket has a rectangular section whose depth is
twice the thickness. Find the cross sectional dimensions of the bracket if the
permissible stress in the material is 50 N/mm2
[AU, Nov / Dec – 2005, 2007]
1.148) A link shaped in the form of a letter S is made up of 30 mm diameter bar, as
shown in fig. Determine the maximum tensile stress and maximum shear stress in
the link. [AU, April / May – 2017]

1.149) The crank hook carries a load of 20KN as shown in figure. The section at X –X
is rectangular whose horizontal side is 100 mm. Find the stresses in the inner and
outer fibers at the given section
1.150) A C-clamp is subjected to a maximum load of W, as shown in figure. If the
maximum tensile stress in the clamp is limited to 140 MPa., find the value of the
load W. [AU, Nov / Dec –2012]

1.151) Determine the maximum shear stress induced in the member loaded as shown in
figure.
1.152) A cylindrical bar of 50 mm diameter and 250 mm long is fixed at one end. At the
free end it is loaded as shown in figure with axial load of 15 KN, a downward
transverse load of 5KN and a torque of 2 KNm. Calculate the maximum stress at point
A of the bar.
1.153) A bolt is subjected to a direct load of 25 KN and a shear load of 15 KN.
Considering the various theories of failure, determine a suitable size of the bolt, if

the material of the bolt is C15 having 200 N/mm2
yield strength.
[AU, May / June – 2007]
1.154) A shaft of diameter 50 mm is subjected to a bending moment of 20 Nm and torque
15 Nm and the yield stress is 200 N/mm2
. Find the factor of safety according to all
theories of failure.
1.155) A steel member is subjected to a 3 dimensional stress system and the resulting
principal stresses are 120 N/mm2
tension, 80 N/mm2
and 40 N/mm2
compression. If
the proportional limit of the material in simple tension is 280 N/mm2
and its Poisson’s
ratio is 0.3, determine the factor of safety according to
(a) Maximum principal stress theory
(b) Maximum principal strain theory
(c) Maximum shear stress theory.
1.156) A machine part is statically loaded and has a yield point strength of 350 N/mm2
.
If the principal stresses are 70 N/mm2
and 35 N/mm2
, both tensile, find the factor of
safety for the following cases. [AU, Nov / Dec – 2015, 2016]
(i) Maximum normal stress theory
(ii)Maximum shear stress theory and
(iii)Distortion energy theory.
1.157) A bolt is subjected to an axial pull of10 kN and a transverse shear force of 5 kN.
The yield strength of the bolt material is 300 MPa. Considering a factor of safety of
2.5. Determine the diameter of the bolt, using (i) maximum normal stress theory, (ii)
maximum shear stress theory, and (iii) maximum principal strain theory. Take
Poisson's ratio as 0.2. [AU, Nov / Dec – 2015]
1.158) A solid circular shaft of diameter 45 mm is loaded by bending moment 650 Nm,
torque 900 Nm and an axial tensile force of 30 kN. The shaft material is ductile with
yield strength of 280 MPa. Determine the factor of safety according to Maximum
principal stress, Tresca and Von misses theories of failure. [AU, April / May – 2017]
1.159) A compound bar of 3m length made up of copper having E = 105GN/m2
and the
other of steel having = 210GN/m2
. Each bar is 25mm broad and 12.5mm thick. This
component bar is stretched by a load of 50kN. Find the increase in length of the
compound bar and the stress produced in the steel and copper. The length of copper
as well as of steel bar is 3m each. [AU, Nov / Dec - 2011]

1.160) A tie - bar has to carry a load of 100 KN. What must be the thickness of bar of
110 mm width, if there is a rivet hole of 22 mm diameter on its, centre line? Working
stress for the tie bar is 75MPa
1.161) A stepped shaft of diameters D and d is subjected to a variable axial load P which
cyclically varies between 0 and 10 KN. The shaft is made of C20 steel, mirror
polished with Su= 500 N/mm2 and Sy = 260 N/mm2. Determine the diameters D and
d with D/d = 1.5, factor of safety = 2, notch sensitivity factor = 0.8 and r/d = 0.2
where r is the shoulder radius.
1.162) A steel rod of yield strength 350N/mm2
and endurance limit of 265 N/mm2
is
subjected to axial load of which varies from -300kN to 700kN and has a stress
concentration factor 1.8. Assume FOS as 2. Calculate the diameter of steel rod
[AU, Apr / May – 2011]
1.163) Determine the thickness of a 120mm wide uniform plate for safe continuous
operation if the plate is to be subjected to a tensile load that has maximum value of
250kN and a minimum values 100kN. The properties of the plate as follows.
Endurance limit stress = 225MPa and yield pint stress 300MPa. The factor of safety
based on yield point may be taken as 1.5. [AU, Nov / Dec - 2011]
1.164) A hot rolled steel shaft of 40mm diameter is subjected to a torsional moment that
varies from 330 Nm to – 110 Nm and an applied bending moment which rises from
440 Nm to –220 Nm. The material of the shaft has an ultimate strength of 550 MN/m2
and yield strength of 410 MN/m2
. Find the approximate factor of safety using

soderberg equation allowing endurance limit to be half the ultimate strength and size
factor and surface finish factor to be 0.85 and 0.62 respectively.
[AU, Nov / Dec – 2008]
1.165) A hot rolled steel shaft is subjected to a torsional moment that varies from 330
Nm clockwise to 110 Nm counter clockwise and an applied bending moment at a
critical section varies from 440 Nm to -220 Nm The shaft is of uniform cross- section
and no keyway is present at the critical section. Determine the required shaft
diameter. The material has an ultimate strength of 550 MPa and yield strength of410
MPa. Take the endurance limit as half the ultimate strength, factor of safety of 2, size
factor of 0.85 and a surface finish factor of 0.62. [AU, Nov / Dec –2013]
1.166) A plate of 12 mm thick, with two holes as indicated in figure below is subjected
to a tensile load of 20 KN. Calculate the stresses at both the holes.
[AU, Nov/Dec – 2004]
1.167) A medium force fit on a 50 mm shaft requires a hole tolerance of 0.025 mm and
a shaft tolerance of 0.016 mm. The maximum interference is to be 0.042 mm. How
will you dimension the hole and the shaft, if hole deviation is H?
[AU, Nov / Dec – 2010]
1.168) A plate of uniform thickness t has two width 45 mm and 30 mm with a fillet
radius of 5 mm. The smaller width portion has a transverse hole of 15 mm diameter
for plate material. The ultimate strength is 200 N/mm2
. Consider stress concentration
factor and assume F.S = 2.5. Find the thickness of the plate for maximum tensile
load of 5 KN. [AU, Nov / Dec – 2006]
1.169) Determine the maximum stress involved in the following cases taking stress
concentration into account.
Case
i) A rectangular plate with a hole under an axial load of 10 KN.

ii) A circular shaft with a step under an axial load of 10 KN.
iii)A shaft under a bending moment of 50 Nm.
iv) A shaft under a twisting moment of 50 Nm.
1.170) A machine component is subjected to a flexural stress which fluctuates between
+300 MN/m2
and -150 MN/mm2
. Determine the value of minimum ultimate strength
according to
i) Gerber relation
ii) Modified Goodman relation
iii)Soderberg relation
Take yield strength = 0.55 ultimate strength; endurance strength = 0.5 ultimate
strength; factor of safety = 2.
1.171) A machine component is subjected to fluctuating stress that varies from 40 to
100 N/mm2
. The corrected endurance limit stress for the machine component is 270
N/mm2
. The ultimate tensile strength and yield strength of material are 600 and 450
N/mm2
respectively. Find the factor of safety using:
(1) Gerber theory
(2) Soderberg line
(3) Goodman line and
(4) Also, find factor of safety against static failure. [AU, May / Jun - 2013]
1.172) A cantilever rod of circular section is subjected to a cyclic transverse load
varying from -100N to +300 N as shown in figure. Determine the diameter d of the
rod by
i) Goodman method ii) Soderberg method.
Using the following data :
Factor of safety = 2; theoretical stress concentration factor = 1.4; notch sensitivity
factor = 0.9; ultimate strength = 550 MPa ; endurance strength = 275 MPa; size
correction factor = 0.85 surface correction factor = 0.9 ; yield strength = 320 MPa

1.173) A cantilever rod of length 120 mm with circular section is subjected to a cyclic
transverse load; varying from -100 N to 300 N at its free end. Determine the diameter
‘d’ of the rod, by (i) Goodman method and (ii) Soderberg method using the following
data. Factor of safety = 2; Theoretical stress concentration factor = 1.4; Notch
sensitivity factor = 0.9; Ultimate strength= 550 MPa; Yield strength = 320 MPa;
Endurance limit = 275 MPa; Size correction factor = 0.85; Surface correction
factor= 0.9. [AU, Nov / Dec – 2015]
1.174) Determine the cross - section of C frame shown in figure to withstand a
maximum load of 25KN. Permissible stress in tension is 100 N/mm2
. Find also the
stresses at X - X. Assume h = 2b
1.175) A cylindrical shaft made of steel of yield strength 700 MPa is subjected to static
loads consisting of bending moment 10 KN-m and a torsional moment 30 KN-m.
Determine the diameter of the shaft using two different theories of failure and
assuming a factor of safety of 2. Take E = 210 GPa and Poisson's ratio = 0.25.
[AU, Nov / Dec – 2012]
1.176) A shaft is subjected to a bending moment varying from - 200 Nm to 500 Nm and
a twisting moment varying from 50 Nm to 175 Nm. The material used has SU = 600
MPa ; Se = 300 MPa; Ka = 0.76; Kb = 0.85; Kc = 0.897; Kt = 1.85 and q = 0.95.
Find the diameter of the shaft by Von Misses Hencky theory. Factor of safety is 1.5
[AU, Nov / Dec – 2003]

1.177) In an elastic material, principal stresses are tensile and compressive and the ratio
being 4 : 1. Determine the limiting stress according to different theories of failure if
the tension test gives the elastic limit of the material as 400 N/mm2
. Assume Poisson's
ratio as 0.3.
1.178) A hot rolled steel shaft is subjected to a torsional load varying from 300 Nm
clockwise to 150 Nm counter clockwise and to a bending moment at a critical section
varying from 400 Nm positive to 200 Nm negative. The shaft has uniform cross -
section and no keyway is present at the critical section. Determine the required shaft
diameter assuming σu = 500 N/mm2
, σy = 400 N/mm2
and n = 2
1.179) A rod of a linkage mechanism made of steel 40Crl(σut = 550 N/mm2
) is subjected
to a completely reversed axial load of 100 kN. The rod is machined on lathe and the
expected reliability is 95%. There is no stress concentration. Determine the diameter
of the rod using a factor of safety of 2 for an infinite life condition.
[AU, Nov / Dec – 2009]
1.180) Determine the diameter of a circular rod made of ductile material with a
endurance limit is 265 MPa and a tensile yield strength of 350 MPa. The member is
subjected to a varying axial load from – 300 kN to 700 kN and has a stress
concentration factor is 1.8. Take factor of safety as 2. [AU, May / June - 2009]
1.181) A shaft of diameter 'd' is subjected to a torque varying between 900 Nm to 1800
Nm. Assuming a factor of safety 2 and a stress concentration factor of 1.2, find the
diameter of the shaft. Take σu = 650 N/mm2
σy = 480 N/mm2
, Size factor B =
0.85 and surface finish factor C = 0.5. [AU, Nov / Dec –2014]
1.182) A cast iron pulley transmits 10 kW at 400 rpm. The diameter of the pulley is 1.2
metre and it has four straight arms of elliptical cross-section, in which the major axis
is twice the minor axis. Determine the dimensions of the arm if the allowable bending
stress is 15 MPa. [AU, May / June - 2009]

1.183) A Cast iron pulley transmits 10 kW at 400 rpm. The diameter of the pulley is 1.2
m and it has four straight arms of elliptical cross-section, in which the major axis is
twice the minor axis. Determine the dimensions of the arm if the allowable bending
stress is 15 MPa. [AU, Nov / Dec –2011]
1.184) A circular bar of length 600mm is supported at its ends. It is acted upon by a
concentrated cyclic load at its centre which varies from 20 KN to 50 KN. If the factor
of safety is 1.5, surface finish factor is 0.9 and the size effect is 0.85. Find the
diameter of the bar. The ultimate strength of the bar is 650 N/mm2
, yield strength is
500 N/mm2
and endurance strength is 350 N/mm2
.
1.185) A circular cross section C45 steel member is subjected to an axial load that varies
from -1000N to 2500N and the torsional moment that varies from 0 to 500Nm.
Assume a factor safety of 1.5 and a stress concentration factor of 1.5. Estimate the
required diameter of the member for indefinite life. [AU, April / May – 2017]
1.186) A 50 mm diameter shaft is made from carbon steel having an ultimate tensile
strength of 630 MPa. It is subjected to a torque, which fluctuates between 2000 Nm
to – 800 Nm. Using Soderberg methods, calculate the factor of safety.
1.187) A simply supported beam has a concentrated load at the center which fluctuates
from a value of P to 4P. The span of the beam is 500 mm and its cross section is
circular with a diameter of 60 mm. Taking for the beam material an ultimate stress
of 700 MPa, a yield stress of 500 MPa, endurance limit of 330 MPa for reversed
bending, and a factor of safety 1.3, calculate the maximum value of P. Take a size
factor of 0.85 and a surface finish factor of 0.9. [AU, Nov / Dec – 2007]
1.188) A steel cantilever is 200 mm long. It is subjected to an axial load, which varies
from 150 N (compression) to 450 N (tension) and also a transverse load at its free
end, which varies from 80 N up to120 N down. The cantilever is of circular cross
section. It is of diameter 2d for the first 50 mm and of diameter d for the remaining
length. Determine its diameter taking a factor of safety 2 Assume the following
values: [AU, May / Jun – 2016]

Yield stress = 330 MPa
Endurance limit in reversed loading = 300 MPa
Correction factors = 0.7 in reversed axial loading
= 1.0 in reversed bending
Stress concentration factor = 1.44 for bending
= 1.64 for axial loading
Size effect factor = 0.85
Surface effect factor = 0.90
Notch sensitivity index = 0.90
1.189) A pulley is keyed to a shaft midway between two antifriction bearings. The
bending moment at the pulley varies from – 170 Nm to 510 Nm as the torsional
moment in the shaft varies from 55 Nm to 165 Nm. The frequency of the variation of
the load is the same as the shaft speed. The shaft is made of cold drawn steel having
an ultimate strength of 538 MPa and yield strength of 400 MPa. Determine the
required diameter for an indefinite life. The stress concentration factor for the
keyway in bending and torsion may be taken as 1.6 and 1.3 respectively. Correction
factor A = 1 (for bending) A = 0.6 (for torsion) B = 0.85, C = 0.88. Use a design
factor N = 1.5 [AU, April / May – 2004, May / Jun - 2012]
1.190) A pulley is keyed to a shaft midway between two antifriction bearings. The
bending moment at the pulley varies from – 160 Nm to 500 Nm as the torsional
moment in the shaft varies from 60 Nm to 160 Nm. The frequency of the variation of
the load is the same as the shaft speed. The shaft is made of cold drawn steel having
an ultimate strength of 540 MPa and yield strength of 400 MPa. Determine the
required diameter for an indefinite life. The stress concentration factor for the
keyway in bending and torsion may be taken as 1.6 and 1.3 respectively. The factor
of safety is 1.5, size factor = 0.80 and surface finish factor = 0.85
[AU, May / Jun - 2012]
1.191) A pulley is keyed to a shaft midway between two bearings. The shaft is made of
cold drawn steel for which the ultimate strength is 550MPa and the yield strength is
400MPa. The bending moment at the pulley varies from -150 N-m to 400 N-m as

the torque on the shaft varies from -50N-m to 150N-m. Obtain the diameter of the
shaft for an indefinite life. The stress concentration factors for the keyway at the
pulley in bending and in torsion are 1.6 and 1.3 respectively. Take the following
values: Factor of safety = 1.5; load correction factors = 1.0 in bending and 0.6 in
torsion; Size factor = 0.85; Surface effect factor = 0.88. [AU, Nov / Dec –2012]
1.192) A transmission shaft made of C 45 steel is subjected to a fluctuating torque
varying from –100 Nm to + 500 Nm. Also, a fluctuating BM acts on the shaft, which
varies from +500 Nm to – 500 Nm. Kt = 2. FS = 1.5. Determine the required
diameter of the shaft. [AU, Nov / Dec – 2005]
1.193) A transmission shaft made of C45 steel is subjected to a fluctuating torque
varying from -100N-m to +500N-m. Also a fluctuating bending moment acts on the
shaft, which varies from +500N-m to -500N-m. Let the stress concentration factor
be 2. The shaft is machined for a FOS 1.5. Determine the required diameter of the
shaft. [AU, April / May – 2010]
1.194) A steel bar is subjected to a reverse axial load of 180kN. Find the diameter of
the bar for a design factor of 2. Ultimate tensile strength 1070N/mm2
, yield strength
910N/mm2
. Endurance limit in bending is half of ultimate strength. Use the following
data. Load factor = 0.7, surface finish factor = 0.85 and stress concentration factor 1
[AU, May / Jun - 2012]
1.195) A bar of circular cross section is subjected to alternating tensile forces varying
from a minimum of 200 KN to a maximum of 500 KN. It is to be manufactured of a
material with an ultimate tensile strength of 900 MPa and an endurance limit of 700
MPa. Determine the diameter of the bar using safety factors of 3.5 related to ultimate
tensile strength and 4 related to endurance limit and a stress concentration factor of
1.65 for fatigue load. Use Goodman straight line as basis for design.
1.196) A circular bar of 500 mm length is supported freely at its two ends. It is acted
upon by a central concentrated cyclic load having a minimum value of 20 kN and a
maximum value of 50 kN. Determine the diameter of bar by taking a factor of safety
of 1.5, size effect of 0.85, surface finish factor of 0.9. The material properties of bar
are given by, ultimate strength of 650 MPa, Yield strength of 500 MPa and
Endurance strength of 350 MPa. [AU, Nov / Dec –2011, 2016]

UNIT – II – SHAFTS AND COUPLINGS
Part – A
2.1) What is meant by a shaft?
2.2) What are the types of the shaft?
2.3) Distinguish between shaft, axle and spindle from the design point of view.
2.4) What is the difference between spindle and axle? [AU, Nov / Dec – 2016]
2.5) What are the materials used in shafts? [AU, Nov / Dec – 2015]
2.6) How are shafts formed?
2.7) State any four reasons for preferring hollow shaft over solid shaft.
2.8) What are the advantage of hollow shafts? [AU, April / May – 2017]
2.9) What is meant by Jack shaft? [AU, April / May – 2010]
2.10) What are the factors to be considered for the selection of shaft materials?
2.11) What is meant by design of a shaft based on rigidity? [AU, Nov / Dec – 2015]
2.12) What are the types of stresses induced in shafts? [AU, Nov / Dec –2011]
2.13) Name the stresses induced in the shaft. [AU, April / May – 2011]
2.14) What are the various stresses induced in the shafts? [AU, May / Jun – 2014]
2.15) What are the various stresses induced in the shafts? [AU, May / Jun – 2014]
2.16) Why is maximum shear stress theory is been used for shaft?
[AU, Nov / Dec - 2009]
2.17) What is the significance of slenderness ratio in shaft design?
[AU, Nov / Dec - 2008]
2.18) Why a hollow shaft has greater strength and stiffness than solid shaft of equal
weight? [AU, April / May – 2011, Nov / Dec –2012, May / Jun – 2016]
2.19) What do you mean by stiffness and rigidity with reference to shafts?
[AU, Nov / Dec - 2010]
2.20) Why is maximum shear stress used for shaft? [AU, Nov / Dec - 2009]
2.21) Define variable load? [AU, April / May – 2010]
2.22) What are the theories of failure used in design of shafts? [AU, Nov / Dec –2012]
2.23) Suggest suitable couplings for
(a) Shaft with parallel misalignment

(b) Shafts with angular misalignment of 10°
(c) Shafts in perfect alignment [AU, Nov / Dec - 2010]
2.24) Explain the significance of slenderness ratio in shaft design.
2.25) Define the term critical speed of the shaft. [AU, Nov / Dec – 2016]
2.26) What is meant by critical speed?
2.27) What is meant by critical speed of shaft? [AU, April / May – 2010]
2.28) What is the effect of key ways cut into the shaft? [AU, May / Jun – 2016]
2.29) How the length and diameter of a shaft affects its critical speed?
[AU, Apr / May – 2015, Nov / Dec – 2016]
2.30) What is meant by equivalent bending moment [AU, May / Jun - 2012]
2.31) Define equivalent torsional moment of a shaft [AU, April / May – 2017]
2.32) Sketch the cross section of a splined shaft. [AU, May / Jun - 2012]
2.33) A shaft is used to transmit 25 KW at 1500 rpm. The material used is 30 C8 steel.
σy = 300 MPa. Find the diameter of the shaft.
2.34) A shaft of 70mm long is subjected to shear stress of 40 MPa and has an angle of
twist equal to 0.017 radian. Determine the diameter of the shaft. Take G=80 GPa.
[AU, Nov / Dec –2013]
2.35) The shaft of diameter 60 mm is subjected to shear stress of 40 MPa and has an
angle of twist equal to 0.01 radian. Determine the length of the shaft for G = 8 *
105
MPa.
2.36) A hollow steel shaft 3 m long transmits 25 KNm torque. The total angle of twist
not exceeding 2° and permissible shear stress is equal to 60 MPa. Find the inner and
outer diameter of the shaft G = 0.8 * 105
MPa.
2.37) Shaft A has diameter which is double the diameter of shaft B of same material
and transmit 80 kW if both shafts rotate at same speed, what is the power
transmitted by shaft B [AU, Nov / Dec –2014]
2.38) What is a key? Where is it used? On what basis is it selected?
2.39) What is key? State its functions. [AU, Nov / Dec –2011]
2.40) What is the function of key? [AU, April / May – 2011]
2.41) What is the function of keys? List types of keys [AU, Nov / Dec –2012]
2.42) How are keys classified?
2.43) Discuss forces on keys. [AU, Nov / Dec –2014]

2.44) For any sunk key, the crushing strength should be at least twice the shear strength.
Prove it.
2.45) What is the main use of woodruff keys? [AU, May / Jun, Nov / Dec –2013]
2.46) What are the advantages of Woodruff keys when compared to others?
2.47) In what ways are splines superior to keys?
2.48) Differentiate between keys and splines.
[AU, May / June – 2009, 2012, Nov / Dec –2011]
2.49) What is coupling? [AU, May / June - 2009]
2.50) What are the different types of rigid couplings? [AU, April / May – 2011]
2.51) Name any two of the rigid coupling. [AU, May / Jun – 2014]
2.52) In what situation is flexible coupling is used? [AU, Nov / Dec – 2008, 2009, 2015]
2.53) Under what circumstances flexible couplings are used?
[AU, Nov / Dec –2012, May / Jun – 2016]
2.54) Differentiate between rigid coupling and flexible coupling.
[AU, May / Jun – 2016]
2.55) Where are spline couplings used?
2.56) State the reasons for which the couplings are located near the bearings.
2.57) Explain the modes of failure of keys.
2.58) What are the forces acting on keys when used for transmitting torque?
2.59) How is the strength of a shaft affected by the keyway?
2.60) State the applications of shaft coupling.
2.61) Name the various types of shaft couplings.
2.62) In which situations, flexible couplings are selected? [AU, Nov / Dec – 2009]
2.63) Name any two of the rigid and flexible couplings. [AU, May / Jun - 2013]
2.64) What are the types of flexible coupling and rigid couplings?
[AU, Nov / Dec – 2016]
2.65) What are the possible modes of failure of the pin (bolt) in a flexible coupling?
[AU, Nov / Dec – 2015]
2.66) What is the use of register in a flange coupling?
2.67) Explain the advantage of split muff coupling over solid muff coupling.
2.68) Explain the failure modes of couplings.

Part – B
2.69) Find the diameter of solid shaft to transmit 20kW at 200rpm. Take FOS 2 and the
shear stresses as 45MPa. If the hollow shaft is need instead of solid shaft. Find the
inside and outside diameter when the ratio between inside and outside diameter is
0.5.
2.70) Compare the weight, strength and stiffness of a hollow shaft of same internal
diameter as that of a solid shaft. The inside diameter of the hollow shaft is being
0.7times the external diameter. Both the shaft has same material and length.
[AU, May / Jun - 2012]
2.71) A solid shaft is to transmit 1000 kW at 120 rpm. Find the shaft diameter if the
shear stress is 80 N/mm2
. If the shaft is made hollow with internal diameter, find the
percentage saving in material, Take I.D = 0.6. [AU, Nov / Dec – 2015]
2.72) A hollow steel shaft transmits 500 KW at 1000 rpm. The maximum shear stress
is 50 N/mm2
. Find the outside and inside diameter of the shaft, if the outside diameter
is twice the inside diameter, assuming that the maximum torque is 20 % greater than
the mean torque.
2.73) A solid shaft of diameter d is used in power transmission. Due to modification of
existing transmission system, it is required to replace the solid shaft by a hollow shaft
of the same material and equally strong in torsion. Further, the weight of hollow shaft
per meter length should be half of the solid shaft. Determine the outer diameter of
hollow shaft in terms of d. [AU, Nov / Dec - 2009]
2.74) A solid circular shaft is subjected to a bending moment of 3000 N-m and a torque
of 10000 N-m. The shaft is made of 45C8 steel having ultimate tensile stress of 700
MPa and a ultimate shear stress of 500 MPa. Assuming a factor of safety as 6,
determine the diameter of the shaft. [AU, May / June - 2009]
2.75) A shaft of 30 KW, 710 rpm motor is 40 mm in diameter and is supported I n
bearings 500 mm apart. Calculate the
(i) Stress due to bending if the armature weighing 10,000 N concentrated at the
Centre acting vertically.
(ii)Stress due to torsion.
(iii)Equivalent shear stress and tensile stress due to bending moment and torque.

2.76) A line shaft rotating at 200 rpm is to transmit 20 KW power. The allowable shear
stress for the shaft material is 42 N/mm2
. If the shaft carries a central load of 900 N
and is simply supported between bearings 3 m apart, determine the diameter of the
shaft. The maximum tensile or compressive stress is not to exceed 56 N/mm2
.
2.77) The shaft of an axial flow rotary air compressor is subjected to a maximum torque
of 2kNm an maximum bending moment of 4kNm. The combined shear and fatigue
factors in torsion and bending may be taken as 1.5 and 2.0 respectively. Determine
the diameter of the shaft, the shear stress in shaft should not exceed 5.0MN/m2
[AU, Nov / Dec - 2008]
2.78) A shaft is to transmit 20KW at 250 rpm. It is supported on two bearings 750mm
apart and has two gears keyed to it. The pinion having 24 teeth of 6mm module is
located at 100mm to the left of the right hand bearing and delivers the power
horizontally to the right. The gear having 80 teeth, 6mm module is located at 150mm
to the right of left - hand bearing and receives power in a vertical direction from
below. Selecting suitable material, determine the required shaft size for a factor of
safety of 2.
2.79) A shaft is supported at its ends with ball bearing carries a straight tooth spur gear
at the mid span of the shaft and transmits 7.5kW at 300rpm. The pitch circle diameter
of the gear is 150mm. The distance between the centerline of bearing and gear is
100mm. If the shaft is made up of steel with allowable shear stress as 45MPa.
Determine the diameter of shaft take the pressure angle of the gear is 20º.

2.80) A steel shaft transmitting 12 KW at 250 rpm is supported on two bearings 700mm
apart and has keyed to it two gears. A - 20 teeth, 8 module gear is located at 120 mm
to the left of the right hand bearing and delivers power to a gear directly below the
shafts. A - 80 teeth, 16 module gear is located at 150 mm to the right of the left -
hand bearing and receives power from a gear directly above it. Sketch the bending
moment diagrams and determine the diameter of the shaft.
2.81) A line shaft is driven by a means of motor placed vertically below it. The pulley
on the line shaft with a diameter of 1.5m and has belt tension of 5.4kN and 1.8kN on
the tight side and slack side of the belt. Both the tension may be assumed vertically.
If the pulley overhangs from the shaft at a distance of 40mm from the line bearing.
Find the diameter of shaft. Take shear stress as 42MPa.
2.82) Power is transmitted to a shaft supported on bearings, 900 mm apart, by a belt
drive, running on a 450 mm pulley, which overhangs the right bearing by 200 mm.
Power is transmitted from the shaft through a belt drive, running on a 250 mm pulley,
located mid - way between the bearings. The belt drives are at right angle to each
other and the ratio of the belt tensions is 3; with the maximum tension in both the
belts being limited to 2 KN. Determine the diameter of the shaft, assuming
permissible tensile and shear stresses are 100 MPa and 60 MPa respectively.
[AU, Nov / Dec – 2004, 2005]
2.83) A shaft is to transmit 50 KW at 1200 rpm. It is also subjected to a bending moment
of 275 Nm. Allowable shear stress is 60 N/mm2
. The shaft is not to twist more than
20
in a length of 2m. G =80 * 103
N/mm2
. Design the shaft.
[AU, Nov / Dec – 2004, 2005]
2.84) A turbine shaft transmits 500 kW at 900 rpm. The permissible shear stress is 80
N/mm2
while twist is limited to 0.50
in a length of 2.5 m. Calculate the diameter of
the shaft. Take G = 0.8 x 105
N/mm2
. If the shaft chosen is hollow with di/d0 = 0.6,
calculate the percentage of saving in material. [AU, May / June – 2007]
2.85) A C45 steel shaft transmits 10 KW at 750 rpm. It is supported on two bearings
800 mm apart and has two gears keyed onto it. The pinion having 30 teeth of 5 mm
module is located 120 mm to the left of the right hand bearing and delivers power
horizontally to the right. The gear having 100 teeth of 5 mm module is located 150
mm to the right of the left hand bearing and receives power from below (CCW

viewed from the left to the end). Determine the diameter of the shaft.
[AU, Nov / Dec – 2001]
2.86) A horizontal nickel steel shaft rest on two bearings, A at the left and B at the right
end and carries two gears C and D located at the distance of 250mm and 400mm
respectively from the centre line of the left end and right bearings. The pitch diameter
of the gear C is 600mm and the gear D is 200mm. The distance between the center
line of the bearings is 2400mm. The shaft transmits 20kW at 120rpm. The power
delivered to the shaft at gear C and taken out at gear D in such a manner that the
tooth pressure FtC of the gear C and FtD act vertically downwards. Find the diameter
of the shaft, if the working stress is100MPa in tension and 56MPa in shear. The gear
C and D weighs 950N and 350N respectively. The combined shock and fatigue
factors for bending and torsion may be taken as 1.5 and 1.2 respectively.
[AU, Nov / Dec – 2012, May / Jun – 2016]
2.87) A transmission shaft is supported on two bearings which are 1m apart. Power is
supplied to the shaft by means of a flexible coupling, which is located to the left of
left hand bearing. Power is transmitted from the shaft by means of a belt pulley, 250
mm diameter, which is located at a distance of 300 mm from the left hand bearing.
The mass of the pulley is 20 kg and the ratio of belt tension on tight and slack sides
is 2:1. The belt tensions act vertically downward. The shaft is made of steel with
yield stress 300N/mm2
and the factor of safety is 3. Determine the shaft diameter, if
it transmits 10 kW power at 360 rpm from the coupling to the pulley
[AU, Nov / Dec – 2010]
2.88) A shaft supported at the ends in ball bearing carries a straight tooth spur gear at
its mid – span and is to transmit 7.5 KW at 300 rpm. The pitch circle diameter of the
gear is 150 mm. The distance between the center line of the bearing and gear are 100
mm each. If the shaft is made of steel and the allowable shear stress is 45 MPa,
determine the diameter. The pressure angle of the gear is 200
.
2.89) A shaft is supported by two bearings placed 1 m apart. A 600 mm diameter pulley
is mounted at a distance of 300 mm to the right of the left hand bearing and this drives
a pulley directly below it with the help of a belt having a maximum tension of 2.25
KN. Another pulley of 400 mm diameter is placed 200 mm to the left of the right
hand bearing and is driven with the help of an electric motor and belt, which is placed

horizontally to the right. The angle of contact for both the pulley is 1800
and =
0.24. Determine the suitable diameter for solid shaft; assume the working stress of
63 MPa in tension and 42 MPa in shear. Assume that the torque on one pulley is
equal to the other pulley. [AU, April / May – 2010, Nov / Dec – 2012]
2.90) A shaft is supported by two bearings placed l100 mm apart. A pulley of diameter
620 mm is keyed at 400 mm to the right of the left hand bearing and this drives a
pulley directly below it with a maximum tension of 2. 75 kN. Another pulley of
diameter 400 mm is placed 200 mm to the left of the right hand bearing and is driven
with a motor placed horizontally to the right. The angle of contact of the pulleys is
180° and the coefficient of friction between the belt and the pulleys is 0.3. Find the
diameter of, the shaft. Assume Kb = 3; Kt = 2.5, Syt = 190 MPa, Sut = 300 MPa
2.91) A mild steel shaft rotating at 720 rpm is supported between two bearings 80 cm
apart. It carries two pulleys A and B at a distance of 30 cm and 60 cm respectively
from the left bearing. 10 KW of power is fed into the pulley A with a diameter of 30
mm by vertical belt drives having the same ratio of driving tensions, which was
observed to be 2.5. Take t = 75 N/mm2
 = 45 N/mm2
. Design the diameter of the
shaft.
2.92) A steel solid shaft transmitting 15 KW at 200 rpm is supported on two bearings
750 mm apart and has two gears keyed to it. The pinion having 30 teeth of 5 mm
module is located 100 mm to the left of the right hand bearing and delivers power
horizontally to the right. The gear having 100 teeth of 5 mm module is located 150
mm to the right of the left hand bearing and receives power in the vertical direction.
Take  = 54 N/mm2
. Design the diameter of the shaft.
[AU, May / Jun – 2013, 2014, Nov / Dec – 2016]
2.93) A mild steel shaft transmits 20 KW at 200 rpm. It carries a central load of 900 N
and is simply supported between the bearings 2.5 m apart. Determine the size of the
shaft, if the allowable  = 42 MPa and the maximum tensile or compressive stress is
not to exceed 56 MPa. What size of the shaft will be required if it is subjected to a
gradually applied load? [AU, Nov / Dec - 2007]
2.94) A mild steel shaft transmits 23 KW at 200 rpm. It carries a central load of 900 N
and is simply supported between the bearings 2.5 m apart. Determine the size of the

shaft, if the allowable  = 42 MPa and the maximum tensile or compressive stress is
not to exceed 56 MPa. What size of the shaft will be required if it is subjected to a
gradually applied load? [AU, Nov / Dec - 2011]
2.95) Design a shaft to transmit power from an electric motor to a lathe head stock
through a pulley by means of a belt drive. The pulley weighs 200 N and is located
at 300 mm from the center of bearing. The diameter of the pulley is 200 m and the
maximum power transmitted is 1 KW at 120 rpm. The angle of lap of the belt is
1800
,  = 0.3. The shock and fatigue factor for bending and torsion are 1.5 and 2.0
Take  = 35 MPa.
2.96) A shaft carries pulley A at the left end and spur gear B at the middle of bearing
supports C and D. The pulley is 1000mm diameter and gear pitch diameter is 600mm.
The pulley is keyed to the shaft at 400mm to the left of the left hand bearing and the
distance between the bearing C and D is 1250mm. The shaft transmits 20Kw and
runs at 750rpm. The shaft receives power from a motor placed vertically below the
pulley through a flat belt with ratio of tension 2.5. The shaft delivers power to a gear
placed horizontally in front. The shaft rotates in ACW direction looking from left =
20.Design the shaft if the weight of A and B are 300N and 250N resp. Allowable
shear stress is 70N/mm2
.Shock and fatigue factor in bending and torsion are 2 and
1.5.
2.97) A solid steel shaft is supported on two bearings 1.8 m apart and rotates at 250
r.p.m. A 20° involute gear D, 300 mm diameter is keyed to the shaft at a distance of
150 mm to the left on the right hand bearing. Two pulleys B and C are located on the
shaft at distances of 600 mm and 1350 mm respectively to the right of the left hand
bearing. The diameters of the pulleys Band Care 750 mm and 600 mm respectively.
30 kW is supplied to the gear, out of which 18.75 kW is taken off at the pulley C and
11.25 kW from pulley B. The drive from B is vertically downward while from C the
drive is downward at an angle of 60° to the horizontal. In both cases the belt tension
ratio is 2 and the angle of lap is 180°. The combined fatigue and shock factors for
torsion and bending may be taken as 1.5 and 2 respectively. Design a suitable shaft
taking working stress to be 42 MPa in shear and 84 MPa in tension.
[AU, May / Jun – 2016]

2.98) An overhung shaft carries a 900 mm diameter pulley, whose centre is 250 mm
from the centre of the nearest bearing. The weight of the pulley is 600 N and the
angle of lap of the belt is 180°. The pulley is driven by a motor vertically below it.
If the permissible tension in the belt is 2600 N and coefficient of friction is 0.3,
determine the diameter of the shaft when internal diameter is 0.6 times the external
diameter. Neglect centrifugal tension and assume permissible shear and tensile
stresses as 64 N/mm2
and 84 N/mm2
. [AU, April / May – 2017]
2.99) A shaft is supported on bearings A and B, 800mm between their centers. A 20
straight tooth spur gear having 600mm pitch diameter is located 200mm to the right
of left hand bearing A and a 700mm diameter pulley is mounted 250mm towards the
left of bearing B. The gear is driven by a pinion with a downward tangential force
while the pulley drives a horizontal belt having 180 angle of wrap. Pulley weight is
2000N. The maximum belt tension is 3000N and tension ratio is 3:1. Determine the
max. B.M and diameter of shaft if allowable shear stress is 40N/mm2
2.100) A 600mm diameter pulley driven by a horizontal belt transmits power through a
solid shaft to a 262mm diameter pinion which drives a mating gear. The pulley
weights 1200N to provide some flywheel effect. The arrangements of elements, the
belt tension and the components of gear actions on the pinion are indicated in fig.
Determine the diameter of shaft Shock and fatigue factor in bending and torsion are
2 and 1.5. [AU, May / June – 2004]
2.101) The shaft of length 1 m carrying two pulleys 1 and 2 at its left and right ends
respectively and it is supported on two bearings A and B which are located 0.25 m
from the left end and the same 0.25 m from the right end respectively. The shaft
transmits 7.5 kW power at 360 rpm from pulley 1 to pulley 2. The diameters of pulley
1 and 2 are 250 and 500 mm respectively. The masses of pulley 1 and 2 are 10 kg
and 30 kg respectively. The belt tension act vertically downward and ratio of belt
tensions on tight side to slack side for each pulley is 2.5:1. The yield strength of the
shaft material σy= 380 MPa and factor of Safety is 3. Estimate the suitable diameter
of the shaft. [AU, Nov / Dec – 2015]
2.102) Compare the weight, strength and stiffness of a hollow shaft of the same external
diameter as that of solid shaft. The inside diameter of the hollow shaft being 0.6
times the external diameter. Both the shafts have same material and length.

2.103) A hollow shaft of 0.5 m outside diameter and 0.3 m inside diameter is used to
drive a propeller of a marine vessel. The shaft is mounted on bearings 6 metre apart
and it transmits 5600 kW at 150 r.p.m. The maximum axial propeller thrust is 500
kN and the shaft weighs 70 kN. Determine (i) The maximum shear stress developed
in the shaft, and (ii) The angular twist between the bearings. [AU, Nov / Dec – 2016]
2.104) A hoisting drum 0.5 m in diameter is keyed to a shaft which is supported in two
bearings and driven through a 12:1 reduction ratio by an electric motor. Determine
the power of the riving motor, if the maximum load of 8 KN is hoisted at a speed of
50m/min and the efficiency of the drive is 80%. Also determine the torque on the
drum shaft and the speed of the motor in r.p.m. Determine also the diameter of the
shaft made of machinery steel, the working stresses of which are 115 MPa in tension
and 50 MPa in shear. The drive gear whose diameter is 450 mm is mounted at the
end of the shaft such that it overhangs the nearest bearing by 150 mm. The combined
shock and fatigue factors for bending and torsion may be taken as 2 and 1.5
respectively [AU, April / May – 2011, Nov / Dec –2013]
2.105) In an axial flow rotary compressor, the shaft is subjected to a maximum twisting
moment of 1500 N-m and a maximum bending of 3000 N-m. Neglecting the axial
load on a shaft determine the diameter of the shaft, if the allowable shear stress is
50N/mm2. Assume Kb = 1.5 and Kt = 1.2. If the shaft is to be a hollow one with di
/ do = 0.4, what will be the material saving in the hollow shaft? It is subjected to the
same loading and of the same material as the solid shaft. Compare the torsional
stiffness of the two shafts. [AU, Nov / Dec –2014]
2.106) Hollow shafts, 0.5 m outside diameter and 0.3 m inside diameter is supported by
two bearings 6 m apart. The shaft is driven by a flexible coupling at one end and
drives a ships propeller at 100 rpm. The maximum thrust on the propeller is 500 kN,
when the shaft is transmitting 5000 KW. The shaft weighs 60 KN. Determine the
maximum shear stress induced in the shafts, considering the weight of the shafts and
column effects. Take shock and fatigue factors as Kt=1 and Kb=1.5.

2.107) The layout of a transmission shaft carrying two pulleys B and C and supported
by two bearings on bearings A and D as shown in fig. Power is supplied to the shaft
by means of a vertical belt on pulley B that is then transmitted to the pulley C
carrying a horizontal belt. The maximum tension in the belt on pulley B is 2.5KN.
The angle of wrap for both pulleys is 180◦
. The shaft is made of plain carbon steel
30C8 (σyt = 400N/mm2
) and FOS is 3. Determine the shaft diameter on strength basis.
2.108) A line shaft supporting two pulleys A and B is shown in figure. Power is supplied
to the shaft by means of a vertical belt on pulley A, which is then transmitted to
pulley B carrying a horizontal belt. The ratio of the belt tensions on the tight and
loose side is 3:1 and the maximum tension in either belt is limited to 2.7 KN. The
shaft is made of plain carbon steel 40C8 (σut = 650 N/mm2
) and σyt = 380 N/mm2
. The
pulleys are keyed to the shaft. Determine the shaft diameter according to the
A.S.M.E code if Kb =1.5 and Kt = 1.0.

2.109) Determine the lowest (i.e, first) critical speed for the shaft of 25mm diameter as
shown in figure.
2.110) Design a shaft to transmit power from an electric motor to a lathe head stock
through a pulley by means of a belt drive. The pulley weighs 200 N and is located at
300 mm from the centre of the bearing. The diameter of the pulley is 200 mm and
the maximum power transmitted is 1 kW at 120 rpm. The angle of lap of the belt is
180° and coefficient of friction between the belt and the pulley is 0.3. The shock arid
fatigue factors for bending and twisting are 1.5 and 2 respectively. The allowable
shear stress in the shaft may be taken as 35 MPa. [AU, Nov / Dec –2011]
2.111) It is required to design a square key for fixing a gear on a shaft of 30mm
diameter. The shaft is transmitting 20kW power at 600 rpm to the gear. The key is
made of steel 50C4 (Syt = 460 N/mm2
) and the factor of safety is 4. For the key
material, the yield strength in compression can be assumed to be equal to the yield
strength in tension. Determine the dimensions of the key. [AU, Apr / May – 2015]

2.112) Design a rectangular key for a shaft of 50mm diameter. The crushing and shear
stress of the key material are 70MPa and 42MPa.
2.113) Design a rectangular key for the following application: A shaft 65 mm diameter
transmits power at maximum shear stress of 67 MPa. The shear stress in the key
should not exceed 75% of the stress developed in the shaft. The key should be at
least 2.5 times strong m crushing compared to shear failure of the key.
2.114) Design a muff coupling to transmit a power of 35 KW from a shaft running at
120rpm. Assume suitable material and stresses.
2.115) Design a muff coupling to connect two shafts transmitting 40kW at 120rpm. The
permissible shear and crushing stress for the shaft and key material are 30MPa and
80MPa respectively. The material of muff is cast iron with permissible shear stress
of 15MPa. Assume that the maximum torque transmitted is 25% greater than the
mean torque. [AU, May / Jun - 2012]
2.116) Design a muff coupling to connect two shafts transmitting 40kW at 150rpm. The
permissible shear and crushing stress for the shaft and key material are 37MPa and
96.25MPa respectively. The material of muff is cast iron with permissible shear
stress of 1.75MPa. Assume that the maximum torque transmitted is 20% greater than
the mean torque. Take width and depth of the parallel key is 22mm and 14mm
respectively [AU, May / Jun - 2012]
2.117) Design a muff coupling to connect two steel shafts transmitting 25kW power at
360 rpm. The Shafts and key are made of plain carbon steel 30C8 (Syt = Syc = 400
N/mm2
). The sleeve is made of gray cast iron FG 200 (Sut = 200 N/mm2
). The factor
of safety for the shaft and key is 4. For the sleeve, the factor of safety is 6 based on
ultimate strength. [AU, Apr / May – 2015, May / Jun – 2016, 2017]
2.118) A rigid flange coupling is to be designed to transmit 20 KW at 1000 rpm.
Assuming suitable stress, design the coupling.
2.119) Design and make a neat dimensioned sketch of a muff coupling which is used to
connect two steel shafts transmitting 40 kW at 350 r.p.m. The material for the shafts
and key is plain carbon steel for which allowable shear and crushing stresses may be
taken as 40 MPa and 80 MPa respectively. The material for the muff is cast iron for

which the allowable shear stress may be assumed as 15 MPa.
[AU, April / May – 2011, Nov / Dec – 2016]
2.120) It is required to design a rigid type of flange coupling to connect two shafts. The
input shaft transmits 37.5 kW power at 180 rpm to the output shaft through the
coupling. The service factor for the application is 1.5, i.e. the design torque is 1.5
times of rated torque. Select suitable materials for various parts of the coupling,
design the coupling and specify the dimensions of its components.
[AU, Nov / Dec - 2009]
2.121) Determine the dimensions of flange coupling that connects a motor and a pump
shaft. The power to be transmitted a 2 kW at a shaft speed of 960 rpm. Select suitable
materials for the parts of the coupling and list the dimensions.
[AU, May / Jun – 2014]
2.122) Design a rigid type of flange coupling to connect two shafts. The input shaft
transmits 37.5 kW power at 180 rpm to the output shaft through the coupling. The
service factor for the application is 1.5. Select suitable material for various parts of
the coupling. [AU, Nov / Dec – 2010]
2.123) A rigid type of coupling is used to connect two shafts transmitting 15 kW at 200
rpm. The shaft, .keys and bolts are made of C45 steel and the coupling is of cast iron.
Design the coupling. [AU, May / Jun - 2013, Nov / Dec – 2016]
2.124) Design a rigid flange coupling to transmit a torque of 250 Nm between two co-
axial shafts. The shaft is made of alloy steel, flanges out of cast iron and bolts out of
steel. Four bolts are used to couple the flanges. The shafts are keyed to the flange
hub. The permissible stresses are given below:
Shear stress on shaft = 100 MPa
Bearing or crushing stress on shaft = 250 MPa
Shear stress on keys = 100 MPa
Bearing stress on keys = 250 MPa
Shearing stress on cast iron = 200 MPa
Shearing stress on bolts = 100MPa
After designing the various elements, make a neat sketch of the assembly indicating
the important dimensions. The stresses developed in the various members may be
checked if thumb rules are using for fixing the dimensions. [AU, Nov / Dec – 2013]

2.125) A rigid coupling is used to transmit 60kW power at 350rpm. There are 6 bolts.
The outer diameter of the flanges is 250mm, while the recess diameter is 175mm.
The coefficient of friction between the flanges is 0.15. The blots are made of steel
45C8 (Syt = 380 N/mm2
) and the factor of safety is 3. Determine the diameter of the
bolts. Assume that the bolts are fitted in large clearance holes.
[AU, Apr / May – 2015]
2.126) Design a cast iron protective flange coupling to transmit 15KW at 900rpm from
an electric motor to a compressor. The service factor may be assumed as 1.35. The
following permissible stress may be used:
Shear stress for the bolt and key material = 40MPa
Crushing stress for the bolt and key = 80MPa
Shear stress for cast iron = 8MPa
2.127) Design a cast iron flange coupling for a mild steel shaft transmitting 90 kW at
250 rpm. The allowable shear stress in the shaft is 40 MPa and the angle of twist is
not to exceed 1° in a length of 20 diameters. The allowable shear stress in the
coupling bolts is 30 MPa. [AU, Nov / Dec – 2007, 2011, 2014]
2.128) Design and draw a cast iron flange coupling for a mild steel shaft transmitting
90kW at 250 rpm. The allowable shear stress in the shaft is 40MPa and the angle of
twist is not to exceed 1º in a length of 20 diameters. The allowable shear stress in
coupling bolt is 30Mpa. [AU, Nov / Dec – 2012]
2.129) Design a protected type flange coupling for the following requirements. Power
to be transmitted= 10 kW. Speed of the shafts = 960 rpm. Select suitable materials
and suitable stresses [AU, Nov / Dec – 2015, April / May – 2017]
2.130) Design a bush type flexible flange coupling to transmit 10 KW at 720 rpm.
Allowable shear stress for shaft, key and bolt may be taken as 50 N/mm2
and the
crushing stress for the key as 110 N/mm2
. The permissible shear stress for the
coupling should be limited to 18 N/mm2
and the bearing pressure between the bush
and the coupling should be limited to 2 N/mm2
.
2.131) Design a bushed pin type of flexible coupling to connect a pump shaft to a motor
shaft transmitting 32kW at 960 rpm. The overall torque is 20% more than mean

torque. The material properties are as follows. The allowable shear and crushing
stress for shaft and key material is 40MPa and 80MPa respectively. The allowable
shear stress for cast iron is 15MPa. The allowable bearing pressure for rubber bush
is 0.8N/mm2
. The material of the pin is same as that of shaft and key. Draw a neat
sketch of the coupling. [AU, Nov / Dec – 2012, May / Jun – 2016]
2.132) Design a bushed pin type of flexible coupling for connecting a motor and a pump
shaft. The following data are provided: Power transmitted = 20 kW; Speed = 1000
rpm; Diameter of the motor and pump shafts = 50 mm; Allowable bearing pressure
in the rubber bush = 0.3 MPa. [AU, Nov / Dec – 2015]
2.133) Design a protective type of cast iron flange coupling for steel shaft transmitting
15 kW at 200 rpm and having an allowable shear stress of 40 N/mm2
. The working
stress in the bolt should not exceed 30 N/mm2
. Assume that the same material is used
for shaft and key that the crushing stress is twice the value of its shear stress. The
maximum torque is 25% greater than the full loaded torque. The shear stress for cast
iron is 14 N/mm2
. [AU, Nov / Dec – 2008, May / Jun – 2016]
2.134) Design a protected type flange coupling for the following requirements. Power
to be transmitted= 10 kW. Speed of the shafts = 960 rpm. Select suitable materials
and suitable stresses [AU, Nov / Dec – 2015]
2.135) Two 35 mm shafts are connected by a flanged coupling. The flanges are fitted
with 6 bolts on 25 mm bolt circle. The shafts transmit a torque of 800 N-m at 350
rpm. For the safe stresses mentioned below, calculate (i) diameter of bolts. (ii)
thickness of flanges, (iii) key dimensions (iv) hub length and (v) power transmitted.
Safe stress for shaft material 63 MPa, Safe stress for bolt material 56 MPa, Safe
stress for cast iron coupling 10 MPa and Safe stress for key material 46 MPa.
[AU, Nov / Dec –2011]
2.136) A flexible coupling is used to transmit 15 kW power at 100 rpm. There are six
pins and their pitch circle diameter is 200 mm. The effective length of bush, the gap
between two flanges and the length of the pin in contact with the right hand flange
are 35, 5 and 23 mm respectively. The permissible shear and bending stresses in the
pin are 35 and 152 N/mm2
respectively. Calculate the pin diameter by shear
consideration, bending consideration. [AU, May / June – 2007]

2.137) A power of 5 KW at 12 rps is transmitted through a flange coupling. Material
for bolt, shaft, and key and flange are C60, C40 and CI grade 30 respectively. Design
the coupling.
2.138) Design a taper key for a shaft of diameter 75 mm transmitting 45 kW at 225 rpm.
The allowable compressive stress as 160 N/mm2
. [AU, May / June – 2007]

UNIT – III – TEMPORARY AND PERMANENT JOINTS
PART – A
3.1) Define screwed joints. What are its basic elements?
3.2) Mention the advantages and disadvantages of screwed joints.
3.3) List the types of commonly used thread forms.
3.4) Name the common type of screw fastenings.
3.5) What is a stud? [AU, Nov / Dec - 2009]
3.6) Sketch a stud [AU, Nov / Dec - 2008]
3.7) What are the different applications of screwed fasteners? [AU, Nov / Dec – 2016]
3.8) What is the use of locking devices in screw fastening?
3.9) How is a bolt designated? Give examples. [AU, May / June – 2009]
3.10) What are the materials for bolts and screws [AU, April / May – 2011]
3.11) What is known as proof strength of the bolts? [AU, Apr / May – 2015]
3.12) What is preloading of bolts? [AU, Nov / Dec – 2015, 2016]
3.13) What is meant by single start and double start thread? [AU, Nov / Dec –2012]
3.14) What do you understand by the single start and double start threads?
[AU, Nov / Dec –2011]
3.15) Define the term self-locking of power screws.
[AU, Nov / Dec –2012, May / Jun - 2013]
3.16) State three conditions where tap bolt are used
3.17) Mention the types of locking devices.
3.18) What are the stresses induced in screwed fastening due to static loading?
[AU, May / Jun – 2016]
3.19) What is the total shear in a double strap butt joint with equal length of straps?
[AU, Nov / Dec – 2015]
3.20) Determine the safe tensile load for a bolt of M20, assuming a safe tensile stress
of 40 MPa. [AU, May / Jun - 2012]
3.21) Determine the safe tensile load for a bolt of M30, assuming a safe tensile stress
of 42 MPa.
3.22) What is threaded joint? [AU, April / May – 2010]
3.23) State the advantages of threaded joints. [AU, May / Jun - 2012]

3.24) What is the meaning of M14 * 2 threaded? [AU, April / May – 2010]
3.25) Why are ACME treads preferred over square thread for power screw?
[AU, Nov / Dec –2014]
3.26) List out the factors that influence the amount of initial tension.
[AU, May / Jun - 2012]
3.27) What is a gib? Why is it provided in a cotter joint
[AU, Nov / Dec –2013, May / Jun – 2016]
3.28) What is a cotter joint?
3.29) What is the purpose of cotter joint? [AU, April / May – 2010]
3.30) What are the applications of a cotter joint?
3.31) What are the types of cotter joints?
3.32) What are different types of cotter joints? [AU, May / Jun – 2014]
3.33) List the advantages of cotter joint over threaded joints. [AU, April / May – 2017]
3.34) What is meant by knuckle joint?
3.35) Where are knuckle joints used? [AU, April / May – 2011]
3.36) Distinguish between cotter and knuckle joints.
3.37) Mention the various methods of failure of knuckle joint.
3.38) Explain the purpose of turn buckle.
3.39) What is rivet? What are its types?
3.40) Give a few examples of detachable joints.
3.41) In what way temporary joint is better than permanent joint?
3.42) Give some examples for permanent and temporary joint.
3.43) What do you understand by the term riveted joint? Explain the necessity of such
a joint.
3.44) State any two advantages of welded joints over riveted joints.
3.45) How are plates riveted?
3.46) Classify the rivet heads according to IS specifications. [AU, Nov / Dec –2011]
3.47) List the four ways by which a riveted joint may fail. [AU, May / Jun - 2012]
3.48) What are the types of fit the diameter of a rivet hole and rivet will have?
3.49) Explain in what way are the riveted joints better than bolted joints.
3.50) Give the list of materials used in rivet manufacture.

3.51) Mention the applications of riveted joint.
3.52) Enumerate the different types of riveted joints and rivets.
3.53) Classify the types of rivet heads.
3.54) Sketch any four types of rivet heads, as recommended by B.I.S.
3.55) What is bearing failure in rivets? [AU, Apr / May – 2015]
3.56) What are caulking and fullering?
3.57) Name the possible modes of failure on riveted joint
[AU, Nov / Dec – 2008, 2012]
3.58) What are the different modes of failure of a riveted joint?
3.59) Explain the failure modes of riveted joints.
3.60) Define the efficiency of a riveted joint.
3.61) What are the assumptions made in designing the boiler joints?
3.62) Mention the assumptions made in riveted joint design. [AU, April / May – 2017]
3.63) According to I.B.R. what is the highest efficiency required for a riveted joint
3.64) Write the Uniwin's formula relating diameter of a rivet hole and thickness of the
plate.
3.65) What type of riveted joint is used in a pressure vessel?
3.66) What is meant by eccentric loading of a riveted joint?
3.67) Write any two advantages .and disadvantages of welded joints over riveted joints.
[AU, May / Jun - 2013]
3.68) Define welding. [AU, Nov / Dec - 2008]
3.69) What are the reasons of replacing riveted joint by welded joint in modern
equipment? [AU, Nov / Dec - 2010]
3.70) What is a welded joint?
3.71) Why are welded joints preferred over riveted joints? [AU, May / June – 2009]
3.72) What are the advantages of weld joints compared with riveted joints
3.73) What are the disadvantages of welding? [AU, Nov / Dec –2014]
3.74) State the advantages of the welded joints. [AU, Nov / Dec – 2015]
3.75) What are the two types of fillet weld? [AU, May / Jun – 2016]
3.76) Under what circumstances are welded joints employed?

3.77) Explain the merits and demerits of welded joint over riveted joint.
3.78) Why are welded joints preferred over riveted joints?
3.79) What are the different methods of welding?
3.80) Classify the welded joint with simple sketches.
3.81) What are two stresses induced in design the design of welding?
[AU, Nov / Dec –2012]
3.82) State the two types of eccentric welded connections.
[AU, Nov / Dec –2013, 2016, May / Jun – 2016]
3.83) What is throat thickness of a fillet weld?
3.84) Why throat is considered while calculating stresses in fillet welds?
3.85) Differentiate with a neat sketch the fillet welds subjected to parallel loading and
transverse loading. [AU, May / Jun – 2014]
3.86) Transverse fillet weld are preferred to parallel fillet welds. Why?
3.87) What is the minimum size for fillet weld? If the required weld size from strength
consideration is too small, how will you fulfill the condition of minimum weld size?
[AU, Nov / Dec – 2008]
3.88) Explain the representation of welded connections on drawings.
3.89) Write down the expression for strength of parallel fillet weld in terms of
permissible shear stress, leg of weld and length of welded joint.
[AU, Nov / Dec - 2009]
3.90) What is the bending stress induced in the weld when a circular rod of diameter d,
welded to a rigid plate by a circular fillet weld of size 't', which is subjected to a
bending moment M? [AU, Nov / Dec – 2015]
3.91) Write a short note on stress concentration in welds.
3.92) Explain eccentric loading of welded joints.
3.93) What is an eccentric loaded welded joint? Describe procedure for designing such
a joint. [AU, May / Jun – 2013, 2014]
3.94) What is the limitation of the single – strap butt joint?

PART - B
3.95) An electric motor weighing 5KN is to be lifted by an eye - bolt which has already
been crewed into it. Design the eye - bolt if the permissible stresses for the bolt
material are 60 MPa and 30 MPa and 80 MPa in tension, shear and crushing
respectively.
3.96) A mild steel cover plate is to designed for an inspection hole in the shell of a
pressure vessel. The hole is 120mm in diameter and the pressure inside the vessel is
6 N/mm2. Design the cover plate along with the bolts. Assume allowable tensile
stress for mild steel as 60MPa and for bolt material as 40MPa.
3.97) A steel bolt of M16x2 is 300mm long carries an impact load of 5000 Nm. If the
threads stop adjacent to the Nut and E = 2.1 x 105 MPa. (i) Find the stress in the root
area (ii) Find the stress if the shank area is reduced to root area.
[AU, Nov / Dec –2014]
3.98) ACME threads are used in a screw lever of a lathe. ACME threads have 50mm
outside diameter and 8mm pitch. The axial pressure required from the screw is
2500N. The collar subjected to thrust in the carriage is 110mm outside diameter and
55mm inside diameter and the load screw rotates at 30rpm. Determine (i) The power
required to drive the lead screw and (ii) The efficiency of the lead screw. Take µ for
the screw as 0.15 and that for collar as 0.12 [AU, April / May – 2010]
3.99) Determine the size of the bolts and the thickness of the arm for the bracket as
shown in figure. If it carries a load of 40KN at an angle of 60° to the vertical.
The material of the bracket and the bolts is same for which the safe stresses can be
assumed 70, 50, 105 MPa for tension, shear and compression respectively.
3.100) Figure shows a solid forged bracket to carry a vertical load of 13.5 kN applied
through the centre of hole. The square flange is secured to the flat side of a vertical
stanchion through four bolts. Estimate the tensile load on each top bolt and the

maximum shearing force on each bolt. Find the bolt size, if the permissible stress is
65 MPa in shear. All dimensions in mm. [AU, Nov / Dec –2016]
3.101) A mild steel cover plate is attached to a cast iron cylinder of 100 mm by means
of 6 studs placed at a radius of 150 mm. The maximum pressure inside the cylinder
is 400 N/mm2
. Design the diameter of the bolt and determine the amount of
prestressing required if the thickness of the cover is 15 mm. The material for the bolt
is C30 steel. The factor of safety is 2. Neglect the stiffness of gaskets. Calculate also
the tightening torque required.
3.102) A steam engine cylinder has a effective diameter of 350mm and the maximum
steam pressure acting on the cylinder cover is 1.25N/mm2
. Calculate the number and
size of studs required to fix the cylinder cover, assuming the permissible stress in the
studs as 33MPa. [AU, Nov / Dec - 2011]
3.103) Determine the size of bolts required to fasten the flanges of a rigid flange
coupling which is used to transmit a power of 20 KW at 1000 rpm. Assume the
allowable shear stress for the shaft and bolt material as 45 N/mm2
.
3.104) A flanged bearing is fastened to a frame by means of four bolts, spaced equally
on 500mm bolt circle. A 250 kN force acts at a distance of 200mm from the frame.
Flange diameter is 600mm. The tensile stress in the bolts is no to exceed 80N/mm2
.
Determine the size of the bolt. [AU, April / May – 2017]
3.105) A cast iron cylinder head is fastened to a cylinder of 500 mm bore with 8 stud
bolts. The maximum pressure inside the cylinder is 2 MPa. The stiffness of the part

is thrice of the bolt. What should be the initial tightening load so that the point is leak
proof at maximum pressure? Also choose a suitable bolt. 2
/300 mmNy  .
[AU, May / Jun – 2014]
3.106) A steam engine cylinder has an effective diameter of 350 mm and the maximum
steam pressure acting on the cylinder cover is 1.25 N/mm2
. Calculate the number
and the size of studs required to fix the cylinder cover. Assume the permissible stress
in the studs to be 70 N/mm2
. [AU, May / June – 2007]
3.107) A steam engine cylinder of 300 mm effective diameter, is subjected to a steam
pressure of 1.5 MPa. The cylinder head is connected by means of 8 bolts having yield
strength of 30 MPa and endurance limit of 240 MPa. The bolts are tightened with an
initial preload of 1.5 times that of steam load. A soft copper gasket is used to make
the joint leak proof assuming a fatigue stress concentration factor of 1.4, and factor
of safety of 2; determine the size of the bolts required. [AU, Nov / Dec – 2015]
3.108) For supporting the travelling crane in a workshop, the brackets are fixed on steel
column as shown in figure. The maximum load on the bracket is 12 KN acting
vertically at a distance of 400 mm from the face of the column. The vertical face of
the bracket is secured to a column by 4 bolts in each row, two at a distance of 50 mm
from the lower edge. Determine the size of the bolt if .84)( max MPat  Find the
cross section. [AU, Nov / Dec –2013]
3.109) A steel plate subjected to a force of 3 KN and fixed to a vertical channel by means
of four identical bolts as shown in figure. The bolts are made of plain carbon steel
45C8 (σyt = 380 N/mm2
) and the factor of safety is 2. Determine the nominal diameter
of the bolt.

3.110) The structural connection shown figure is subjected to an eccentric force P of 10
kN with an eccentricity of 500 mm. The center distance between bolts 1 and 2 is 200
mm and 1 and 3 is 150 mm. All the bolts are identical. Assume  = 80 N/mm2
for bolt
material. Design the size of the bolts. [AU, Nov / Dec – 2008]
3.111) A steel plate subjected to a force of 5 kN and fixed to a channel by means of
three identical bolts is shown in Fig. The bolts are made from plain carbon steel
45C8 and the factor of safety is 3. Specify the size of bolts. [AU, April / May – 2017]
3.112) A steam engine of effective diameter 300 mm is subjected to a steam pressure of
1.5 N/mm2
. The cylinder head is connected by 8 bolts having yield point 330 MPa
and endurance limit at 240 MPa. The bolts are tightened with an initial preload of

1.5 times the steam load. A soft copper gasket is used to make the joint leak-proof.
Assuming a factor of safety 2, find the size of bolt required. The stiffness factor for
copper gasket may be taken as 0.5. [AU, Nov / Dec – 2007, 2012, May / Jun – 2016]
3.113) The cylinder head of a steam engine is subjected to a steam pressure of 0.7
N/mm2
. It is held in position by means of 12 bolts. A soft copper gasket is used to
make the joint leak-proof. The effective diameter of cylinder is 300 mm. Find the
size of the bolts so that the stress in the bolts is not to exceed 100 MPa.
[AU, May / June – 2009]
3.114) Bolts are used to hold the cover plate on a pressure level, which is subjected to
an internal pressure varying from zero to 2 MPa. The area over which the pressure
acts may be taken to correspond to 400 mm diameter circle. The bolts are preloaded
to the extent of 1.3 times the maximum force exerted by the fluid on the cover plate.
The combined stiffness of the parts, held together by the bolt (including copper
gasket), is four times the stiffness of the bolt. Following data is given for the bolts :
Ultimate tensile strength = 900 N/mm2
.
Endurance limit in bending = 300 N/mm2
.
Fatigue stress concentration factor = 2.2
Factory of safety = 1.5
Number of bolts = 8
Determine the size of the bolts assuming fine thread. [AU, May/June – 2009]
3.115) A blotted joint is used to connect two components. The combined stiffness of
the components is twice the bolt stiffness. Initial tightening load is 5kN. The external
force is 10kN creates further tension on the bolt. The bolt is made of plain carbon
steel 30C8 for which yield strength in tension is 400N/mm2
. Using a factor of safety
of 3 and assuming coarse threads, select suitable blot size. [AU, May / Jun - 2012]
3.116) Two lengths of mild steel tie rod having a width of 200mm are to be connected
by means of Lozenge joint with two cover plates to withstand a tensile load of
180kN. Completely design the joint, if the permissible stresses are 80MPa in tension;

65MPa in shear and 160MPa crushing. Draw a neat sketch of the joint.
[AU, May / Jun - 2012]
3.117) Design a knuckle joint to transmit 150 kN. The design stresses may be taken as
75 MPa in tension, 60 MPa in shear and 150 MPa in compression.
[AU, May / June – 2009, Nov / Dec –2011, 2012, 2016]
3.118) Two bars are connected by a knuckle joint and the bars are subjected to a tensile
load of F. List all the possible modes of failures and the governing relationship of
determine the dimensions of the elements. [AU, April / May – 2010]
3.119) Design a knuckle joint to connect two circular rods subjected to an axial tensile
force of 50kN. The rods are co axial and a small amount of angular movements
between their axes is permissible. Design the joint and specify the dimensions of its
components. Select suitable materials for the parts. [AU, April / May – 2010]
3.120) Design a knuckle joint for transmitting an axial load of 60 KN, for the following
stresses
(i) In tension 60 MPa
(ii)In compression 75 MPa
(iii)In shear 40 MPa. Sketch the joint
3.121) Design a knuckle joint to withstand a load of 100 kN. All the parts of the joint
are made of the same material with σut =σuc = 480 MPa, andτu= 360 MPa. Use factor
of safety of 6 on ultimate strength. [AU, Nov / Dec – 2015]
3.122) A knuckle joint is to transmit a force of 140 KN. The allowable stresses in
tension, shear and compression are 75N/mm2
, 65 N/mm2
and 140 N/mm2
respectively.
Design the joint. [AU, Nov / Dec – 2004, 2015, May / Jun – 2016]
3.123) A pin in a knuckle joint is subjected to an axial load of 90 KN. Assume that the
thickness of the eye is to be 1.5 times the diameter of the pin. The allowable stress
of the material in tension and compression due to bending is 60 MPa and allowable
stress is 20 MPa. Determine the required pin diameter. [AU, Nov / Dec – 2004]
3.124) Design and draw a knuckle joint to connect two mild steel bars under a tensile
load of 25kN. The allowable stresses are 65MPa in tension, 50MPa in shear and
83MPa in crushing. [AU, May / Jun - 2012]

3.125) Two rods subjected to a tensile force of 50 kN are connected by means of knuckle
joint. Steel 30C8 and the factor of safety is 5. Design the joint and specify the
dimensions of its components.
3.126) Design cotter joint to support a load of 6kN. Permissible design stresses are
In tension = 60 N/mm2
Crushing = 90 N/mm2
Shear = 40 N/mm2
3.127) A socket type cotter joint is to be designed for a pull of 32kN. Steel having the
following maximum permissible stresses is used.
Permissible stress in tension = 56 N/mm2
Permissible stress in compression = 70 N/mm2
Permissible stress in shear = 39 N/mm2
3.128) Design and draw a cotter joint to support a load varying from 30 kN in
compression to 30 kN in tension. The material used in carbon steel for which the
following allowable stresses may be used. The load is applied statically
Tensile stress = 50 MPa
Compressive stress = 50 MPa
Shear stress = 50 MPa
Crushing stress = 90 MPa [AU, May / Jun - 2013]
3.129) Design a socket and spigot cotter joint to transmit a load of 50 kN. Assume t =
60 N/mm2
 = 45 N/mm2
c = 100 N/mm2
.
3.130) Design a sleeve and cotter joint subjected to a load of 30 kN for the steel used,
take the permissible stress as.
In tension = 55 N/mm2
In crushing = 70 N/mm2
In shear = 35 N/mm2
.

3.131) Design a Gib and cotter joint which carries a maximum load of 35 kN. Assuming
that the Gib rod and cotter are of same material and have the following allowable
stresses. t = 20 Mpa,  =15 Mpa, c = 50 Mpa
3.132) Derive an expression to find out the maximum shear stress in transverse fillet
weld. [AU, May / June – 2009]
3.133) Find the efficiency of the following riveted joints:
(i)Single riveted lap joint of 6 mm plates with 20 mm diameter rivets having a
pitch of 50 mm.
(ii)Double riveted lap joint of 6 mm plates with 20 mm diameter rivets having a
pitch of 65 mm.
Assume
Permissible tensile stress in plate = 120 Mpa
Permissible shearing stress in rivets = 90 Mpa
Permissible crushing stress in rivets = 180 Mpa.
3.134) Design a double riveted butt joint with two cover plates for the longitudinal
steam of a boiler shell 1.5 m in diameter subjected to steam pressure of 0.95 N/mm2
.
Assume joint efficiency as 75%, allowable tensile stress in the plate 90 MPa;
compressive stress 140 MPa and shear stress in the rivet 56 MPa.
[AU, Nov / Dec – 2016]
3.135) A plate of 100 mm wide and 12.5 mm thick is to be welded to another plate by
means of two parallel fillet welds. The plates are subjected to a load of 50KN. Find
the length of the weld so that the maximum stress does not exceed 56 N/mm2
. (Do
the calculation under static loading) [AU, Oct / Nov – 1999]
3.136) Determine the length of welds required to transmit a load of 54.5 kN between
12.7mm thick plates, when the plates are to be joined by (i) Two parallel fillet welds
(ii) Two transverse fillet welds. Also solve this problem for fatigue loading.
3.137) Determine the size of the weld for a bar as in figure, when it is loaded in the
following manner
(i)Subjected to an axial load of 75 KN

(ii)Subjected to a bending moment of 500 N - mm. Allowable stress in the weld
is 900 N/mm2
Determine the stress in the weld when it is subjected to a bending moment of
500 N-mm if the same bending moment is produced by a load of 2000 N at the
end.
3.138) A butt welded joint with ground and flush surface is subjected to tensile load
which varies from 50kN to 100kN. Plates are 10mm thick. Determine the length of
weld required for over 2,500,000 cycles. [AU, Apr / May – 2015]
3.139) Determine the size of the weld for a bar as shown in figure, when it is loaded in
the following manner.
(i) Subjected to an axial load of 75 KN
(ii) Subjected to a bending moment of 500 N/mm allowable stress in the weld is 900
N/mm2
Determine the stress in the weld when it is subjected to a bending moment of 500
N/mm if the same bending moment is produced by a load of 2000 N at the end.
3.140) A circular bar of 50 mm diameter and 200 mm long is welded to a steel plate. It
supports a vertical downward load of 10 KN at its free end. Determine the weld size
assuming the strength of the weld to be 94 MPa. [AU, April / May – 2010]

3.141) Design the joint for welding a bracket B to the column C as shown in Fig. The
safe welding stress in the welds may be taken as 80 N/mm2
[AU, Nov / Dec – 2008]
3.142) A is in the form of a steel pipe of 100 mm internal diameter and 400 mm long is
welded to the vertical side of a structure by an all-round fillet weld. The thickness
of pipe is 8 mm. Determine the size of weld if it has the same strength as that of the
pipe. What load can be supported at the end of the cantilevers if the permissible stress
is 100 N/mm2
?
3.143) A spherical pressure vessel with a 500 mm inner diameter, is welded from steel
plates. The welded joints are sufficiently strong and do not weaken the vessel. The
plates are made from cold drawn steel 20 C8 (σut= 440 N/mm2
. and σyt= 242 N/mm2
).
The vessel is subjected to an internal pressure which varies from zero to 6 N/mm2
.
The expected reliability is 50% and the factor of safety is 3.5. The vessel is expected
to withstand infinite number of stress cycles. Calculate the thickness of the plate.
3.144) Determine the length of the weld run for the plate of size 120mm wide and 15mm
thick to be welded to another plate by means of
(i) A single transverse weld and
(ii)Double parallel fillet welds when the joint is subjected to variable loads.
3.145) A bracket carrying a load of 20 kN is to be welded as shown in Figure. Calculate
the size of the weld if the working shear stress is not to exceed 70 N/mm2
[AU, Nov / Dec – 2010]

3.146) A welded joint as shown in figure, is subjected to eccentric load of 2 kN. Find
the size of the weld, if the maximum shear stress in the weld is 25MPa.
[AU, Nov / Dec – 2012]
3.147) A bracket is welded to the vertical plate by means of two fillet welds as shown
in fig. and is subjected to an eccentric load of 2500N. Determine the size of welds if
permissible shear stress is limited to 50N/mm2
3.148) A bracket is welded to a vertical column by means of two fillet welds as shown
in fig. Determine the size of the welds, if the permissible shear stress is limited to 70
N/mm2
. [AU, April / May – 2017]

3.149) A welded connection is subjected to an eccentric force of 7.5KN. Determine the
size of welds if the permissible shear stress for the weld is 100 N/mm2
. Assume static
conditions.
3.150) A welded connection, as shown in figure is subjected to eccentric force of 60kN
in the plane of welds. Determine the size of the welds, if the permissible shear stress
for the weld is 90 N/mm2
. Assume static conditions. [AU, Apr / May – 2015]
3.151) A plate 90mm wide and 15mm thick is welded on to another plate by a single
transverse weld and a double parallel fillet weld. Find the length of the parallel fillet
weld if the plate is loaded by a static tensile load, take the allowable tensile stress of
the plates as 70N/mm2
and weld shear stress as 55N/mm2
.

3.152) An eccentrically loaded plate is welded to a frame as shown in figure. Design
the welded joint if the tensile stress in the plate should not exceed 100 N/mm2
and
that in the weld 80 N/ mm2
.
3.153) The figure shows an angle welded to a column and carries a static load F as
shown in figure. Determine the ratio of weld lengths La and d Lb, forces Fa and Fb in
terms of F.
3.154) A plate of width 240mm is welded to a vertical plate by placing it on the vertical
plate to form a cantilever with a projecting length of 480mm and the overlap between
the plates as 120mm. Fillet welding is done between the plates on all the three sides.
A vertical load of 35kN is applied on the cantilever at its free and parallel to the
width. If the allowable stress of the weld is 94MN/m2, determine the weld size.
lb

3.155) Find the maximum shear stress induced in the weld of 6 mm size when a channel,
as shown in figure, is welded to a plate and loaded with 20 kN. Force at a distance
of 200 mm. [AU, Nov / Dec –2013]
3.156) Determine the size of weld required for the joint shown in figure allowable stress
in the weld is 85 N/mm2
.
3.157) A 12.5 x 19.5 x 1cm angle is welded to a frame by two 1 cm fillet welds. A load
of 10 kN is applied normal to the center of gravity axis at a distance of 500mm from
the center of gravity of welds. Find the maximum shear stress in the welds, assuming
each weld to be 100mm long and parallel to the axis of the angle.

1cm
cm
cm
500mm
cm
KN
3.158) A plate 75 mm wide and 12.5 mm thick is joined with another plate by a single
transverse weld and a double parallel fillet weld as shown below. The maximum
tensile and shear stresses are 70 Mpa and 56 Mpa respectively. Find the length of
each parallel fillet weld, if the joint is subjected to both static and fatigue loading.
3.159) A plate 100 mm wide and 12.5 mm thick is to be welded to another plates by
means of parallel fillet welds. The plates are subjected to an axial load of 50KN. Find
the length of the weld so that maximum stress does not exceed 56 N/mm2
if the joint
is under (a) static loading and (b) fatigue loading. [AU, Nov / Dec - 2011]

3.160) A shaft of rectangular cross section is welded to a support plate by means of fillet
weld on its own end as shown in figure below. If the size of weld is 6 mm, find the
maximum normal and shear stress in the weld.
3.161) A rectangular beam is to be welded to a plate. The maximum load of 14 N is
applied repetitiously. Determine the size of weld required for 10,000,000 cycle.
Assume the shear load is distributed uniformly over the entire weld as shown in
figure below. [AU, April / May – 2004]
3.162) A shaft of rectangular cross section is welded to a support by means of fillet
welds as shown in figure. Determine the size of the weld, if the permissible shear
stress in the weld is limited to 75 N/mm2
. [AU, Nov / Dec – 2008]

3.163) A 50 mm diameter solid shaft is welded to a flat plate as shown in figure in below.
If the size of the weld is 15 mm, find the maximum normal and shear stress in the
weld. [AU, May / June 2007, 2014, Nov / Dec – 2007]
200 m m
5 0 mm
S
t
10 KN
3.164) A cylindrical beam of size 60 mm is attached to support by a complete
circumferential fillet weld of 6mm. find (i) torque and (ii) bending moment that can
be applied if limiting shear stress is 140 MPa. [AU, Nov / Dec –2014]
3.165) A welded connection shown in figure below is subjected to an eccentric force of
7.5 KN. Determine the size of welds if the permissible shear stress for the weld is
100 N/mm2
. Assume static conditions. [AU, May / June – 2007]
3.166) A 50 mm diameter solid shaft is welded to a flat plate as shown in figure. If the
size of the weld is 15 mm, find the maximum normal and shear stress in the weld.
[AU, May / June – 2009]

3.167) A rectangular cross-section bar is welded to a support by means of fillet welds
as shown in fig (i). Determine the size of the welds, if the permissible shear stress in
the weld is limited to 75 MPa. [AU, Nov / Dec –2011]
3.168) A rectangular steel plate is welded as a cantilever to a vertical column and
supports a single concentrated load P, as shown in figure. Determine the weld size if
shear stress in the same is not to exceed 140 MPa.
[AU, Nov / Dec – 2012, 2016, May / Jun – 2013, 2016]
3.169) A double riveted lap joint is made between 15 mm thick plates. The rivet
diameter and pitch are 25 mm and 75 mm respectively. If the ultimate stresses are
400 Mpa in tension, 320 Mpa in shear and 640 Mpa in crushing, find the minimum
force per pitch which will rupture the joint.
3.170) A rectangular steel plate 100mm wide is welded to a vertical plate to form a
cantilever with an overlap of 50mm and overhang of 150mm. It carries a vertical
downward load of 60kN at free end. Fillet weld is done on three sides of the plate.
The permissible stress is 140N/mm2
. Determine the size of the weld.
[AU, May / Jun – 2012, 2016, Nov / Dec – 2015]
3.171) A triple butt joint with unequal cover plates is used to connect two 16 mm plates
of a boiler. Design the joint completely if allowable stresses are 50, 40 and 80 N/mm2

in tension, shear and crushing respectively for the plate and rivet material. Find also
the efficiency of the joint.
3.172) A double riveted lap joint with zig - zag riveting is to be designed for 13 mm
thick plates. Assume.t = 80 Mpa,  = 60 Mpa, c = 120 Mpa. Find the efficiency of
the joint.
3.173) Two lengths of mild steel tie rod having width 200 mm and thickness 12.5 mm
are to be connected by means of a butt joint with double cover plates. Design the
joint if the permissible stresses are 80 Mpa in tension, 65 Mpa in shear and 160 Mpa
in crushing. Make a sketch of the joint.
3.174) Two 12 mm thick tie plates are connected by a lap riveted joint. The tie plates
carry a load of 150 kN. Calculate (a) width of plates (b) diameter and number of
rivets (c) efficiency of the joint.
3.175) The recommended design stresses are 100 N/mm2
in tension, 80 N/mm2
in shear
and 160 N/mm2
in crushing for the plate and rivets respectively.

UNIT – IV – ENERGY STORING ELEMENTS AND ENGINE
COMPONENTS
PART – A
4.1) What is a spring?
4.2) What is the use of springs? [AU, Nov / Dec - 2008]
4.3) Give some of materials used for spring [AU, Nov / Dec - 2008]
4.4) Give a list of the different types of springs
4.5) Mention any four types of springs. [AU, May / Jun - 2012]
4.6) Distinguish between close coiled and open coiled springs. [AU, Nov / Dec –2014]
4.7) Explain the following terms of the spring. (a) Free length (b) Spring index
4.8) Define (a) Spring Index (b) Spring rate. [AU, Nov / Dec –2011]
4.9) Define spring rate. [AU, May / Jun – 2016]
4.10) Define spring index and spring constant. [AU, Nov / Dec –2012]
4.11) What are the functions of springs? In which type of spring is the behavior non -
linear?
4.12) State any two functions of springs. [AU, Nov / Dec – 2016]
4.13) Write the formula for natural frequency of spring. [AU, Nov / Dec –2012, 2016]
4.14) What are the different materials used for manufacturing springs?
4.15) What is the difference between open coiled and close coiled springs?
4.16) Explain helical spring. What are its types?
4.17) What is stiffness of spring? [AU, Nov / Dec – 2015, May / Jun – 2016]
4.18) Obtain the expression for stiffness of helical spring. [AU, May / Jun - 2012]
4.19) When a helical compression spring is cut into two halves, what is the stiffness of
the resulting half spring? [AU, April / May – 2017]
4.20) Two springs of stiffness K1 and K2 are connected in series. What is the stiffness
of the connection [AU, April / May – 2010]
4.21) For a springs in series, the spring rate ( stiffness) add reciprocally prove
4.22) How will you find whether the given helical spring is a compression or tension
spring?

4.23) What is Whal’s factor? Why it is used? [AU, April / May – 2011]
4.24) Why is Wahl’s factor to be considered in the design of helical compression
springs? [AU, April / May – 2010]
4.25) What is the effect of change in spring index on Whal’s factor and on the stress
induced in a helical compression spring? [AU, Apr / May – 2015]
4.26) Sketch the stresses induced in the cross section of a helical spring, considering
Wahl's effect. [AU, April / May – 2017]
4.27) What are the different styles of end for helical compression spring?
[AU, Nov / Dec - 2009]
4.28) What type of spring is used to maintain an effective contact between a cam and a
reciprocating roller or flat faced follower? [AU, Nov / Dec – 2015]
4.29) What are conical springs?
4.30) Explain torsion spring.
4.31) On what basis are the materials for helical springs selected? Give some of the
materials used for spring.
4.32) What is the effect of increase in wire diameter on the allowable stress value?
[AU, Nov / Dec - 2010]
4.33) Define solid length and free length of the helical spring.
4.34) Define the terms stiffness and spring index.
4.35) What is pitch?
4.36) On what concepts are helical springs designed?
4.37) What are the different types of stresses induced in coil springs?
4.38) Why is Wahl's factor to be considered in the design of helical compression
springs?
4.39) A helical spring of rate 10 N/mm is mounted on top of another spring of rate 8
N/mm. Find the force required to give a total deflection of 45 mm.
4.40) A helical spring of rate 12 N/mm is mounted on the top of another spring of rate
8 N/mm. Find the force required to give a deflection of 50mm.
[AU, Nov / Dec –2013]
4.41) What is meant by eccentric loading of springs?
4.42) The extension springs are in considerably less that the compression springs. Why?
[AU, Nov / Dec –2011]

4.43) Explain buckling of compression springs.
4.44) What is meant by surge in springs? [AU, Nov / Dec – 2008, 2012]
4.45) What is surge in springs? [AU, May / Jun - 2013]
4.46) Explain surge in coil springs.
4.47) Estimate the equivalent stiffness of springs in parallel and in series.
4.48) What are the purposes of using concentric springs? [AU, Apr / May – 2015]
4.49) What are the applications of concentric springs? [AU, Apr / May – 2010]
4.50) When two concentric springs of stiffness 100 N/mm and 50 N/mm respectively
are subjected to an axial load of 750 N, what will be the deflection of each spring?
[AU, Nov / Dec – 2007]
4.51) Explain briefly leaf springs. [AU, Nov / Dec - 2009]
4.52) What are the advantages of the leaf springs?
4.53) What is semi - elliptical leaf springs?
4.54) What is meant by semi elliptical leaf springs? [AU, May / Jun – 2014]
4.55) What is meant by nipping in leaf springs?
4.56) What is nipping of leaf spring? [AU, Nov / Dec – 2015, May / Jun – 2016]
4.57) What is master leaf and how are the lengths of various leaves determined?
4.58) Why are leaf springs made in layers instead of a single plate?
4.59) What is a lever? [AU, Nov / Dec –2011]
4.60) What is a flywheel? For what purpose is it used?
4.61) What is the use of flywheel? [AU, Nov / Dec - 2008, May / Jun - 2012]
4.62) What is the function of a flywheel? [AU, Apr / May – 2011, Nov / Dec –2012]
4.63) What is the main function of a flywheel in an engine? [AU, Nov / Dec –2011]
4.64) What is the purpose of flywheel that is used in an IC engine?
[AU, Nov / Dec –2013]
4.65) How does the function of flywheel differ from that of governor?
[AU, May / Jun – 2012, Nov / Dec –2012, 2016]
4.66) What is the purpose of the flywheel? [AU, Nov / Dec – 2015]
4.67) What are the types of stresses induced in a flywheel rim?
4.68) Write the difference between flywheel and governor.
4.69) Specify the types of flywheel.

4.70) Define co-efficient of fluctuation of speed. [AU, Nov / Dec –2011]
4.71) Define Co-efficient of fluctuation of speed in flywheel. [AU, May / Jun - 2013]
4.72) Define (a) Coefficient of fluctuation of speed (b) Coefficient of fluctuation of
energy. [AU, Nov / Dec –2014]
4.73) Define the term 'fluctuation of speed' and 'fluctuation of energy'.
[AU, May / Jun – 2016]
4.74) Define the term co-efficient of steadiness. [AU, Nov / Dec – 2009, 2011]
4.75) Define the term "fluctuation of energy". [AU, May / Jun – 2014]
4.76) Define co-efficient of fluctuation of energy. [AU, Nov / Dec - 2009]
4.77) What type of stresses is produced in a disc flywheel? [AU, Nov / Dec - 2010]
4.78) Explain briefly the stresses induced in a flywheel.
4.79) Explain how the size of the flywheel can be determined.
4.80) What are the major failure in a crankshaft? What is it due to?
4.81) At what angle of the crank the twisting moment is maximum in the crankshaft?
[AU, Nov / Dec –2011]
4.82) What is the use of connecting rod?
4.83) Why is I-section preferred for the connecting rod?
4.84) Why I section is chosen for the connecting rod of I.C engines?
[AU, Nov / Dec – 2015]
4.85) Sketch the cross section of connecting rod at mid-span.
4.86) Why is piston end of a connecting rod kept smaller than the crank pin end?
[AU, Nov / Dec - 2010]
4.87) Under what force, the big end bolts and caps are designed?
[AU, Nov / Dec –2011]
4.88) What type of external forces act on connecting rod? [AU, Nov / Dec –2012]
4.89) What are the forces acting on connecting rod? [AU, April / May – 2017]
PART - B
4.90) Design a spring for a balance to measure 0 to 1000 N over a scale of length 80
mm. The spring is to be enclosed in a casting of 25 mm diameter. The approximate

number of turns is 30. The modulus of rigidity is 85 KN/mm2. Also calculate the
maximum shear stress induced.
4.91) One helical spring is nested inside another; the dimensions are as tabulated below.
Both the springs have the same free length and carry a total load of 2500 N.
Outer spring Inner springs
Number of active coils 6 10
Wire diameter 12.5 mm 9mm
Mean coil diameter 100 mm 70 mm
Determine the
(i) Maximum load carried by each spring
(ii) Total deflection of each spring
(iii) Maximum stress in each spring. Take G = 83 GPa.
4.92) Design a spring for a spring loaded safety valve for the following conditions.
Operating pressure 10 bar. Diameter of the valve seat 100mm. Design shear stress
for the spring material is 400 N/mm2
. Modulus of rigidity is 8.00 x 104
N/mm2
. The
spring is to be kept in a casing of 120 mm inner diameter and 350mm long. The spring
should be at maximum lift to 6mm, when the pressure is 11 bar.
4.93) A spring loaded safety valve for a boiler is required to blow-off at a pressure of
1.5 N/mm2
. The diameter of the valve is 60 mm. Design a suitable compression
spring for the safety valve, assuming the spring index to be 6 and 25 mm initial
compression. The maximum lift of the valve is 15 mm. The shear stress in the spring
material is to be limited to 450 MPa. Take G = 0.84 * 105
MPa.
4.94) A spring for a spring balance is to elongate 100mm, when subjected to a load of
20Kgf. Assume that the mean diameter of the coil is to be 6 times the diameter of the
wire and the maximum stress to be induced is limited to 40 Kgf/mm2
. Determine the
diameter for the wire, for the coil and the number of coils required and length of
spring. Modulus of rigidity G.=0.8 x104Kgf/mm2
.
4.95) A helical compression spring of the exhaust valve mechanism is initially
compressed with a preload of 375 N. When the spring is further compressed and the

valve is fully opened, the torsional shear stress in. the spring wire should not exceed
750 N/mm2
. Due to space limitations, the outer diameter of the spring should not
exceed 42 mm. The spring is to be designed for minimum weight. Calculate the wire
diameter and the mean coil diameter of the spring. [AU, April / May – 2017]
4.96) Design and draw a valve spring of a petrol engine for the following operating
conditions:
Spring load when the valve is opened = 400 N
Spring load when the valve is closed = 250 N
Maximum inside diameter of spring = 25 mm
Length of the spring when the valve is opened = 40 mm
Length of the spring when the valve is closed = 50 mm
Maximum permissible shear stress = 400 MPa
4.97) Design a helical spring for a spring loaded safety valve of the following
conditions:
Diameter of valve seat = 65mm
Operation pressure = 0.7N/mm2
Maximum pressure when the valve blows freely = 0.75N/mm2
Maximum lift of the valve when the pressure rises
from 0.7 to 0.75N.mm2
= 3.5mm
Maximum allowable stress = 550MPa
Modulus of rigidity = 84kN/mm2
Spring index = 6
Draw a neat sketch of the free spring showing the main dimensions.
[AU, Nov / Dec - 2012]
4.98) A safety valve of 60 mm diameter is to blow off at a pressure of 1.2 N/mm2
. It is
held on its seat by a closed coil helical spring. The maximum lift of the valve is 10

mm. Design a suitable compression spring of C = 5 and providing an initial
compression of 35 mm.  = 500 MPa, G = 80 KN/mm2
. Calculate the
a) Diameter of the spring wire b) Mean coil diameter
c) Number of active turns d) Pitch diameter of the coil.
[AU, May / Jun – 2013, 2016]
4.99) Design a helical tension spring for a spring loaded safety valve for the following
conditions.
Diameter of valve seat = 65 mm.
Operating pressure = 0.7 N/mm2
Maximum pressure = 0.75 N/mm2
.
Maximum lift of the valve when the pressure ranges from 0.7 to 0.75 N/mm2
is 3.5
mm. = 550 MPa , G = 84 KN/mm2
, C = 6
4.100) Design a tension spring to be used for a balance measure 0 to 2000 N over a scale
of length 100mm. The spring is to be enclosed in a casing whose inside diameter is
30mm. Approximate number of coils is 30. Take the modulus of rigidity as 0.5*105
MPa. Also calculate the maximum shear stress induced. [AU, April / May – 2017]
4.101) Design a close-coiled helical spring of silicon-manganese steel for the valve of
an IC engine capable of exerting a net force of 65N when the valve is open and 54N
when the valve is closed. The internal and external diameters are governed by space
limitations, as it has to fit over bushing of 19 mm outside diameter and go inside a
space of 38 mm diameter. The valve lift is 6 mm. [AU, Nov / Dec - 2010]
4.102) A helical compression spring is used to absorb the shock. The initial compression
of the spring is 30 mm and it is further compressed by 50 mm while absorbing the
shock. The spring is to absorb 250 J of energy during the process. The spring index
can be taken as 6. The spring is made of patented and cold drawn steel wire with
ultimate strength of 1500 N/mm and modulus of rigidity of 81370 N/mm2
. The
permissible shear stress for the spring wire should be taken as 30% of the ultimate
tensile strength. Design the spring and calculate [AU, Nov / Dec - 2009]

4.103) A helical compression spring is used to absorb the shock. The initial compression
of the spring is 30 mm and it is further compressed by 50 mm while absorbing the
shock. The spring is to absorb 250 J of energy during the process. The spring index
can be taken as 6. The spring is made of patented and cold drawn steel wire with
ultimate strength of 1500 N/mm and modulus of rigidity of 81370 N/mm2
. The
permissible shear stress for the spring wire should be taken as 30% of the ultimate
tensile strength. Design the spring and calculate : [AU, Nov / Dec - 2009]
(i) Wire diameter
(ii) Mean coil diameter
(iii)Number of active turns
(iv) Pitch of the turns
4.104) A close-coiled helical compression spring has plain ends and is to fit over a 25
mm diameter rod. When a compressive force of 100 N is applied to the spring it
compresses by 50 mm. If the spring has a preferred wire diameter of 4 mm, and the
spring material has a maximum allowable shear stress of 180 MN/m2
and a modulus
of rigidity of 81 GN/m2
, determine [AU, May / Jun – 2014]
(i) The mean coil diameter of the spring.
(ii)The diametrical clearance between the spring and the rod.
(iii) The number of coil in the spring
(iv) The solid length of the spring.
4.105) Design a compression spring for a static load for the given data; the spring thrust
must give a minimum force of 455 N and maximum force of 682 N over an
adjustment range of 18.75 mm deflection. Use the least expensive, unpeened, cold
drawn spring wire since the load is static. Ultimate strength = 1318 MPa, Modulus
of Rigidity G = 79.6 GPa. Mass density = 8300 kg/m3
[AU, Apr / May – 2010]
4.106) A helical valve spring is to be designed for an operating load range of
approximately 90 to 135 N. The deflection of the spring for the above load range is
about 7.5mm. Assuming severe service and spring index of 10, determine the size
of wire, size and number of coils and pitch recommend [AU, Nov / Dec - 2008]

4.107) Design a closed coiled helical spring subjected a tensile load of magnitude varying
from 2500 N to 3000 N and the axial deflection of spring for this range of load is 6.5
mm. Design the spring, taking the spring index as 6 and safe shear stress for material
equal to 465 MPa. [AU, Nov / Dec –2014]
4.108) At the bottom of a mine shaft, a group of 10 identical close coiled helical springs
are set in parallel to absorb the shock caused by the falling of the cage in case of
failure. The loaded cage weighs 75 KN, while the counterweight has a weight of 15
KN. If the loaded cage falls through a height of 50 m from the rest, find the maximum
stress induced in each spring if it is made of 50 mm diameter steel rod. The spring
index is 6 and the number of active turns in each spring is 20. Take G = 80 KN /
mm2
.
4.109) A rail wagon of mass 20 tonnes is moving with a velocity of 2 m/sec. It is
brought to rest by two buffers with spring of 300 mm diameter. Maximum deflection
is 250 mm. Take  = 60 MPa. Design the spring for buffer.
4.110) A railway wagon moving at a velocity of 1.5 m/s is brought to rest by bumper
consisting of two helical springs arranged in parallel. The mass of the wagon is 1500
kg. The springs are compressed by 150 mm in bringing the wagon to rest. The spring
index can be taken as 6. The springs are made of oil-hardened and tempered steel
wire with ultimate tensile strength of 1250 MPa and modulus of rigidity of 81.37
GPa. The· permissible shear stress for the spring wire can be taken as 50% of the
ultimate tensile strength. Design the spring and calculate (i) wire diameter (ii) mean
coil diameter (iii) number of active coils (iv) total number of coils (v) solid length
(vi) free length and (vii) pitch of the coil. [AU, Nov / Dec – 2015]
4.111) A loaded narrow gauge car of mass 1800 kg and moving at a velocity 72 m/min,
is brought to rest by a bumper consisting of two helical steel spring of square section.
The mean diameter of the coil is 6 times the side of the square section. In bringing
the car to rest, the springs are to be compressed 200 mm Take  = 365 MPa and C =
6.
4.112) A helical compression spring made of oil tempered carbon steel, is subjected to
a load which varies from 600 N to 1600 N. Take C = 6 and FOS = 1.25. If the yield
shear stress is 770 MPa and endurance stress in shear is 350 MPa, the compression
at the maximum load is 30 mm. Assume G = 80 GPa. Find the size of the spring

wire and the mean diameter of the spring coil, no of turns, pitch and free length.
[AU, May / Jun – 2016]
4.113) A helical compression spring made of oil tempered carbon steel is subjected to
a load which varies from 400 N to 1000 N. The spring index is 6 and the design
factor of safely is 1.25. If the yield stress in shear is 770 MPa and endurance stress
in shear is 350 MPa, find: (i) Size of the spring wire, (ii) Diameter of the spring. (iii)
Number of turns of the spring, and (iv) Free length of the spring. The compression
of the spring at the maximum load is 30 mm. The modulus of rigidity for the spring
material may be taken as 80 kN/mm2
. [AU, Nov / Dec –2013, 2016]
4.114) A helical spring is to support a load of 1000 N. The spring is guided by a rod of
50 mm diameter. The spring undergoes a deflection of 40 mm under the load.
Determine the diameter of the wire and the number of turns required. Use C - 60
steel with a factor of safety of 2.
4.115) Derive the stress equation for a helical spring. [AU, Nov / Dec – 2007]
4.116) Design a helical compression spring for a maximum load of 1500 N for a
deflection of 30 mm using the value of spring index as 5. The maximum permissible
shear stress for spring wire is 420 MPa and modulus of rigidity is 84 kN/mm2
.
[AU, Apr / May – 2011]
.
[AU, Apr / May – 2015]
.
[AU, Nov / Dec – 2007]
4.119) Design a closed coiled helical compression spring for a service load ranging
from 2.5 KN to 3KN. The deflection for this load range is 6mm. Use a spring index
of 5. Take the shear yield strength as 700 N/mm2
and modulus of rigidity as 8 x
104
N/mm2
. Factor of safety is not to be less than 1.3. Also check the spring of
buckling.

from 2.5 KN to 3KN. The deflection for this load range is 6mm. Use a spring index
of 5. Take the shear yield strength as 700 N/mm2
and modulus of rigidity as 8 *
104
N/mm2
. Factor of safety is not to be less than 1.3. Also check the spring of
buckling.
from 2.25 KN to 2.75KN. The deflection for this load range is 6mm. Use a spring
index of 5. Take the permissible shear stress intensity as 420 N/mm2
and modulus of
rigidity as 84 x 103
N/mm2. Neglect the effects of stress concentration. Draw a fully
dimensioned sketch of the spring, showing the details of the finish of the end coils.
[AU, Nov / Dec – 2012]
4.122) Design and draw a valve spring of a petrol engine for the following operating
conditions:
Spring load when the valve is open = 400 N
Spring load when the valve is closed = 250 N
Maximum inside diameter of the spring = 25 mm
Length of the spring when the valve is open = 40 mm
Length of the spring when the valve is closed = 50 mm
Maximum permissible shear stress = 400 MPa.
[AU, Apr / May – 2011]
4.123) A helical spring is made from a wire of 6mm diameter and outside diameter of
70mm. the spring has 6 numbers of active coils. If the permissible stress in shear is
300N/mm2
and the modulus of the rigidity is 80kN/mm2
, find the axial load which
the spring can take and the deflection produced. [AU, May / Jun - 2012]
4.124) A helical spring is made from a wire of 8 mm diameter and is of outside diameter
75 mm. The spring has 6 numbers of active coils. If the permissible stress in shear is
350 N/mm2
and the modulus of rigidity is 84 kN/mm2
. Find the axial load, which the
spring can take and the deflection produced. [AU, Nov / Dec – 2015]

4.125) A helical torsion spring of mean diameter 600 mm is made of a round wire of 6
mm diameter. If a torque of 6 Nm is applied on the spring, find the bending stress
induced and the angular deflection of spring in degrees. Take C = 10, E = 200
KN/mm2
. The number of effective turns may be taken as 5.5.
4.126) A concentric spring for an aircraft engine valve is to exert a maximum force of
5 KN under a axial deflection of 40mm. Both the springs have the same free length,
same solid length and are subjected to equal maximum shear stress of 500 N/mm2
. If
the spring index for both the springs is 6, find the (a) load shared by each spring (b)
main dimensions of both the springs, and (c) number of active coils of each spring.
Assume G = 0.8 x 105
N/mm2
and diametral clearance to be equal to the difference
between the wire diameters.
4.127) A concentric spring is used as a valve spring in a heavy duty engine. It consists
of two helical compression springs having the same free length and same solid
length. The composite spring subjected to a maximum force of 6000N and the
corresponding deflection is 50mm. The maximum torsional shear stress induced in
spring is 800 N/mm2
. The spring index of each spring is 6. Assume the same material
for two springs and the modulus of rigidity of the spring is 8137 N/m2
. The diametral
clearance between the coils is equal to the difference between the wire diameters.
Calculate [AU, April / May – 2010]
(i) The axial force transmitted by the spring.
(ii) Wire and mean coil diameters of each springs
(iii) Number of active coils in each springs
4.128) A truck spring has 10 leaves and is supported at a span length of 100 cm, with a
central band of 80 mm wide. A load of 6 KN is applied at the center of spring whose
permissible stress is 300 N/mm2
. The spring has a ratio of total depth to width of
about 2.5. Determine the width, thickness, deflection and length of all leaves.
4.129) A load of 10 tones is supported on a 4 leaf springs, each consisting of 10 leaves.
The span of each spring is 80cm and the material of the spring is having permissible
tensile stress of 6 N/mm2
and E = 2*105
N/mm2
. The maximum deflection allowed
is 80cm. Design a spring. [AU, Nov / Dec – 2008]

4.130) A truck spring has 12 numbers of leaves, two of which are full length leaves.
The spring supports are 10.5 m apart and the central band is 85mm wide. The central
load is to be 5.4 kN with a permissible stress of 280 MPa. Determine the thickness
and width of the steel spring leaves. The ratio of the total depth to the width of the
spring is 3. Also determine the deflection of the spring. [AU, May / June – 2009]
4.131) A truck spring has 12 numbers of leaves, two of which are full lengthy leaves.
The spring supports are 1.05 m apart and the central band is 85 mm wide. The central
load is to be 5.4 kN with a permissible stress of 280 MPa. Determine the thickness
and width of the steel spring leaves. The ratio of the total depth to the width of the
spring is 3. Also determine the deflection of the spring.
[AU, Nov / Dec – 2007, 2011]
4.132) A locomotive spring has an overall length of 1.5 m and sustains a load of 85 KN
at its center. The spring has 3 full - length leaves and 15 graduated leaves with a
central band of 120 mm wide. All the leaves are stressed to 430 N/mm2
when fully
loaded. The ratio of spring depth to width is 3. Take E = 2.1 x 105
N/mm2
.
(i)Find the width and thickness of the leaves
(ii)Find the initial space that should be provided between the full - length leaves
(iii)Graduated leaves before the band load is applied.
(iv)When will the load be exerted on the band after the spring is assembled?
4.133) A locomotive spring has an overall length of 1.1m and a sustained load of 75 KN
at its center. The spring has 3 full length leaves and 15 graduated leaves with a
central band of 100 mm wide. All leaves are to be stressed to 420 N/mm2
. When
fully loaded, the ratio of the spring depth to width is to be approximately 2. Take E
= 2.1 X 105
N/mm2
.
(i) Determine the width and thickness of leaves
(ii)Determine the initial space that should be provided between the full length and
graduated leaves before the band load is applied.
(iii)What load is exerted on the band after the spring is assembled?
4.134) A Belleville spring is made of silicon steel. The spring compresses completely
flat when it is subjected to axial force of 4500N. The corresponding maximum stress
is 1375 *106
N/m2.
Assume do/di = 1.75 and h/t 1.5. Calculate
(i) Thickness of washer

(ii) Free height of washer minus thickness (h)
(iii) Outer diameter of washer
(iv) Inner diameter of washer [AU, April / May – 2010]
4.135) A semi-elliptic leaf spring consists of two extra full-length leaves and eight
graduated length leaves, including the master leaf. The centre-to-centre distance
between the two eyes of the spring is 1m. The maximum force acting on the spring
is 10KN and the width of each leaf is 50 mm. The spring is initially preloaded in
such a way that when the load is maximum, the stresses induced in all the leaves are
equal to 350N/mm2
. The modulus of elasticity of the leaf material is 207 KN/mm2
.
Determine the i) thickness of leaves and ii) deflection of the spring at the maximum
load.
4.136) A locomotive semi-elliptical laminated spring has an overall length of 1 m and
sustains a load of 70 kN at its centre. The spring has 3 full length leaves and 15
graduated leaves with a central band of 100 mm width. All the leaves are to be
stressed to 400 MPa, when fully loaded. The ratio of the total spring depth to that of
width is 2. Take young modulus is 210 kN/mm2
. Determine (i) the thickness and
width of the leaves (ii) the initial gap that should be provided between the full length
and graduated leaves before the band load is applied and (iii) the load exerted on the
band after the spring is assembled. [AU, Nov / Dec –2011]
4.137) A semi - elliptic spring has an overall length of 1.1m and sustains a load of 70
KN at its center. The spring has 3 extra full length leaves and 13 graduated leaves
with a central band of 100mm wide. All the leaves are to be stressed equally without
exceeding 420 N/mm2
when fully loaded. The total depth of spring is twice the width.
If the Young’s modulus is 2.1 x 105
N/mm2
, determine the
(i) Thickness and width of leaves
(ii)Nip to be provided for prestressing.
(iii)Load exerted on the clipping bolts after the spring is assembled.
[AU, Nov / Dec – 2006]
4.138) A semi - elliptic leaf spring is of 1 m long and is required to resist a load of 50
KN. The spring has 15 leaves, of which three are full length leaves. The width of

the central band is 100 mm. All the leaves are to be stressed to 420 MPa. The ratio
of the total depth to width is 3. Take E = 2.1 X 105
MPa.
Determine the
(i) Thickness and width of the leaves
(ii) Initial gap that should be provided between the full length and graduated
leaves before assembly and
(iii) Load exerted on the band for the assembly.
4.139) A semi - elliptic laminated truck spring to carry a load of 6000 N is to consist of
seven leaves 65 mm wide, two of the leaves extending the full length of the spring.
The spring is to be 1.1 m long and attached to the axle by two U - bolts 80mm apart.
The bolt holds the central portion of the spring so rigidly that they may be considered
equivalent to a band having a width equal to the distance between the bolts. Assume
a design stress for spring material as 350N/mm2
. Determine the (i) thickness of
leaves, (ii) deflection of spring (iii) diameter of the eye, (iv) initial bending radius of
the leaves and (v) length of leaves. [AU, May / June – 2007]
4.140) Design a leaf spring for a truck to the following specifications:
Maximum load on the spring = 140 kN
Number of springs = 4
Material = Chromium vanadium steel
Permissible tensile stress = 600 N/mm2
.
Maximum number of leaves = 10
Span of spring = 1000 mm
Permissible deflection = 80 mm
Young’s modulus of the spring = 2 *105
N/mm2
[AU, Nov / Dec – 2008, 2012, April / May – 2011]
4.141) Design a leaf spring for a truck to the following specifications:
Maximum load on the spring = 100 kN
Factor of safety = 2
Number of springs = 4

Material = Chromium vanadium steel
Permissible Ultimate stress = 1380MPa.
Maximum number of leaves = 8
Full length leaves = 2
Graduated leaves = 6
Span of spring = 1000 mm
Width of the central band = 150 mm
Permissible deflection = 100 mm
Young’s modulus of the spring = 206 *103
MPa
[AU, Apr / May – 2015]
4.142) Design a leaf spring for the following specifications: Total load = 140 kN;
Number of springs supporting the load = 4; Maximum number of leaves = 10; Span
of the spring = 1000 mm; Permissible deflection= 80 mm. Take Young's modulus,
E = 200 kN/mm2
and allowable stress in spring material as 600 MPa.
[AU, Nov / Dec – 2016]
4.143) A leaf spring for a small trailer is to support a load of 10kN. The spring has 6
graduated leaves and 2 extra full length leaves of spring steel of safe stress 360MPa.
The overall length is 1.2m and the central band is 75mm wide. Taking the ratio of
total depth of leaves to width as, design the spring. [AU, May / Jun - 2012]
4.144) A disc spring made up of sheet steel with outer diameter 125mm and inner
diameter 50mm the spring is dished to a height of 4.5mm. The maximum stress
550MPa. Determine the load and deflection of spring.
4.145) The flywheel of a punching machine must be capable of supplying 2600 Nm of
energy in order to punch a hole. The flywheel is 1.25 mm in mean diameter and
rotates at 150 rpm when running at a normal speed. Determine the cross sectional
area required for the rim of the cast iron flywheel if the co-efficient of fluctuation of
speed limit to 0.15.
4.146) A multi cylinder engine is to run at a constant load with a speed of 600 rpm. On
drawing the crank effort diagram to scale of 1cm = 2500 Nm and 1cm = 300
, the area
above and below the mean torque line in sq. cm are as follows.
+1.6, -1.72, +1.68, -1.91, +1.97, - 1.62.

The speed is to be kept within 1 % of the mean speed of the engine. Find suitable
dimensions of a cast-iron flywheel rim assuming suitable proportions.
[AU, Nov / Dec – 2006]
4.147) Design a cast-iron flywheel having six arms for a four stroke engine developing
70 KN at 300 rpm. The mean diameter of the flywheel may be taken as 1.2m.
The fluctuation of speed is 2.5% of the mean speed. The work done during power
stroke is 1.4 times the average work done during the whole cycle. The peripheral
speed is limited to 30 m/sec. Allowable shear stress for shaft and key material is
40N/mm2
and tensile stress for cast-iron is 20 N/mm2
. Take the width of the rim to
be twice its thickness and the major axis of the elliptical arms to be twice the minor
axis.
4.148) The torque developed by the engine is given by following equation
T = 14250 + 2200sin2θ - 1800cos2θ
Where T is the torque in Nm and θ is crank angle from inner dead center position.
The resisting torque of the machine is constant throughout the work cycle. The
coefficient of fluctuations is 0.01. The engine speed is 150rpm. A solid circular steel
disk 50mm, thick is used as a flywheel. The mass density is 7800kg/m3
. Calculate
the diameter of the flywheel disc. [AU, Apr / May – 2011, 2017]
4.149) Design and draw suitable flywheel for a four stroke four cylinder 133 Kw engine
running at 375 rpm. Due to space restriction the flywheel diameter should not exceed
1.2m [AU, Nov / Dec – 2010]
4.150) Rimmed flywheel made of grey cast-iron (mass density = 7100 kg/m3
) is used
on a punching press running at a mean speed of 200 rpm. The punching operation
consists of one quarter revolution during which the flywheel is required to supply
3000Nm of energy. The co-efficient of speed fluctuation is limited to 0.2. The rim,
which contributes 90% of the required moment of inertia, has a mean radius of 0.5m
due to space limitations. The cross section of the rim is square. Determine its
dimensions.
4.151) A 5 kW induction motor, running at 960 rpm operates a riveting machine. The
flywheel fitted to it, is of mass 120 kg, with radius of gyration equal to 0.35 m. Each
riveting takes 1 second and requires 9 kW. Determine (i) the number of rivets formed

per hour and (ii) the reduction in speed of the flywheel, after the riveting operation.
[AU, Nov / Dec – 2015]
4.152) Design a C I flywheel for a four stroke engine developing 150KW at 200 rpm.
Calculate the mean diameter of the flywheel if the hoop stress is not to exceed 4
MPa. The total fluctuation of speed is to be 4% of mean speed. The work done
during the power stroke is 1.5 times the average work done during the cycle. Density
of CI is 7200 kg/m3
. [AU, Nov / Dec – 2003, 2014]
4.153) Design a C.I rim type flywheel with six arms, for a four stroke diesel engine
developing 100KN. The peak torque may be assumed to be 12 times the mean torque
and the maximum fluctuation of energy is 70% of the energy per cycle. The load of
the engine is constant. The engine runs at the speed of 1000 rpm and the speed of
fluctuation is limited to 20 rpm. Assume suitable stresses.
4.154) A punching machine makes 25 working strokes per minute and is capable of
punching 25 mm diameter holes in 18 mm thick steel plates having ultimate shear
strength of 300 MPa. The punching operation takes place during 1/10th
of a
revolution of the crankshaft. Estimate the power needed for the driving motor,
assuming mechanical efficiency of 95%. Determine suitable dimensions for the rim
cross-section of the flywheel, which is to revolve at 9 times the speed of the
crankshaft. The permissible co-efficient of fluctuation of speed is 0.1. The diameter
of the flywheel must not exceed 1.4 m owing to space restrictions. Check for the
centrifugal stress induced in the rim. [AU, May / June – 2007]
4.155) A punching press pierces 35 holes per minute in a plate using 10kN-m of energy
per hole during each revolution. Each piercing takes 40 per cent of the time needed
to make one revolution. The punch receives power through a gear reduction unit
which in tum is fed by a motor driven belt pulley 800 mm diameter and turning at
210 r.p.m. Find the power of the electric motor if overall efficiency of the
transmission unit is 80 per cent. Design a cast iron flywheel to be used with the
punching machine for a coefficient of steadiness of 5, if the space considerations
limit the maximum diameter to 1.3 m. Allowable shear stress in the shaft material =
50 MPa, Allowable tensile stress of cast iron= 4 MPa, Density of cast iron = 7200
kg/m3
. [AU, May / Jun – 2016]

4.156) A punching machine carries out punching 10 holes per minute. Each hole of 36
mm diameter in 16 mm thick plate requires 7 N-m of energy/mm2
of the sheared
area. The punch has a stroke of 90 mm. Determine the power of the motor required
to operate the machine. If the total fluctuation of speed is not to exceed 2.5% of the
mean speed; determine the mass of the flywheel. The mean speed of the flywheel is
15m/s. [AU, April / May – 2017]
4.157) A machine punching 38 mm holes in 32 mm thick plate requires 7 N-m of energy
per sq. mm of sheared area, and punches one hole in every 10 seconds. Calculate the
power of the motor required. The mean speed of the flywheel is 25 meters per second.
The punch has a stroke of 100 mm. find the mass of the flywheel required, if the total
fluctuation of speed is not to exceed 3% of the mean speed. Assume that the motor
supplies energy to the machine at uniform rate. [AU, May / Jun - 2013]
4.158) A single cylinder double acting steam engine delivers 185 KW at 100 rpm. The
maximum fluctuation of energy per revolution is 15% of energy developed per
revolution. The speed variation is limited to 1% either way from the mean. The
mean diameter of the rim is 2.4 m. Design a cast iron flywheel for the engine.
[AU, April / May – 2001, May / Jun – 2012, 2016, Nov / Dec –2013, 2016]
4.159) Design a cast iron flywheel used for a four stroke I.C engine developing 180kW
at 240rpm. The hoop or centrifugal stress developed in the flywheel is 5.2MPa, the
total fluctuation of speed is to be limited to 3% of the mean speed. The work done
during the power stroke is 1/3 more than the average work done during the whole
cycle. The maximum torque on the shaft is twice the mean torque. The density of the
cast iron is 7220kg/m3
[AU, Nov / Dec - 2012]
4.160) During one revolution of the crank of multi cylinder engine the area above and
below the mean turning moment line in order are 36, 81, 75, 64, 92, and 58 sq.mm.
the horizontal scale is 1cm = 45° and the vertical scale 1cm = 720N m. Find the area
of the cross section of the rim of the fly wheel required to limit the total fluctuation
of speed to 3% of mean speed which is 150 rpm. The mean speed of the rim is
1000m/min and density of the rim is 7260kg/m3
[AU, Nov / Dec - 2008]
4.161) A rimmed flywheel made of grey cast iron (mass density = 7100 kg/m3
) is used
on a punching press running at the speed of 200 rpm. The punching operation consist
of one quarter revolution during which the flywheel is required to supply 3000 N-m

of energy. The co efficient of speed fluctuation is limited as 0.2. the rim which
contributes 90% of the required moment of inertia has been mean radius of 0.5m due
to space limitations. The cross section of the rim in square. Determine its dimensions.
[AU, Apr / May – 2010]
4.162) A multi cylinder engine is to run at a constant load at a speed of 600 rpm. On
drawing the crank effort diagram to scale of 1 mm = 250 N-m and 1 mm = 3o
, the
areas in square mm above and below the mean torque line were measured and found
to be in order +160, -172, +168, -191, +197 and -162. The speed is to be kept within
± 1% of the mean speed of the engine. Determine the moment of inertia of the
flywheel. [AU, May / June – 2009, Apr / May – 2011]
4.163) A multi cylinder engine is to run at a constant load at a speed of 600 rpm. On
drawing the crank effort diagram to scale of 1 mm = 250 N-m and 1 mm = 3°, the
areas in square mm above and below the mean torque line were measured and found
to be in order +160, –172, +168, –191, +197 and –162. The speed is to be kept with
in ±1% of the mean speed of the engine. Determine the moment of inertia of the
flywheel. Also determine suitable dimensions for cast iron flywheel with a rim
whose breadth is twice its radial thickness. The density of cast iron is 7250 kg/m3
,
and its working stress in tension is 6 MPa. Assume that the rim contributes 92% of
the flywheel effect. [AU, Nov / Dec –2011]
4.164) The turning moment diagram of a multi cylinder engine is drawn with a scale of
(1mm - 1o
) on the abscissa and (1mm = 250 N-m) on the ordinate. The intercepted
areas between the torque developed by the engine and the mean resisting torque of
the machine, taken in order from one end are – 350 + 800 - 500 + 900 - 550 + 450
and - 650 mm2
. The engine is running at a mean speed of 750 rpm and the coefficient
of speed fluctuations is limited to 0.02. A rimmed flywheel made of grey cast iron
FG 200 ( = 7100 kg / m3
) is provided. The spokes, hub and shaft are assumed to
contribute 10% of the required moment of inertia. The rim has rectangular cross
section and the ratio of width to thickness is 1.5. Determine the dimensions of rim.
[AU, Nov / Dec - 2009]
4.165) The areas of the turning moment diagram for one revolution of a multi cylinder
engine with reference to the mean tuning moment, below and above the line, are -
32, +408, -267, +333, -310, +226, -374, +260 and -244 mm2
. The scale for abscissa

and ordinate are: 1 mm=2.4º and 1 mm = 650 N-m respectively. The mean speed is
300 r.p.m. with a percentage speed fluctuation of ± 1.5%. If the hoop stress in the
material of the rim is not to exceed 5.6 MPa, determine the suitable diameter and
cross section for the fly-wheel, assuming that the width is equal to 4 times the
thickness. The density of material may be taken as 7200 kg/m3
. Neglect the effect of
the boss and arms. ][AU, May / Jun – 2014, Nov / Dec – 2016]
4.166) An engine runs at a constant load at a speed of 480rpm. The crank effort diagram
is drawn to a scale 1mm = 200 N-m torque and 1mm = 3.6˚ crank angle. The areas
of the diagram above and below the mean torque line in mm2
are in the following
order: +110, -132, +153, -166, +197, - 162. Design a flywheel if the total fluctuation
of the speed does not exceed 10rpm and the centrifugal stress in the rim is not to
exceed 5MPa. Assume that the rim breadth is approximately 2.5times the rim
thickness and 90% of the moment of inertia is due to rim. The density of the material
of the flywheel is 7250kg/m3
. Make a sketch of the flywheel giving the dimensions
of the rim, the mean diameter of the rim and the other estimated dimensions of spoke,
hub etc. [AU, May / Jun - 2012]
4.167) A single cylinder double acting steam engine delivers 185 kW at 100 rpm. The
maximum fluctuation of energy per revolution is 15 percent of the energy developed
per revolution. The speed variation is limited to 1 percent either way from the mean.
The mean diameter of the rim is 2.4 m. Design the suitable flywheel.
[AU, Nov / Dec – 2007]
4.168) A single cylinder double acting steam engine delivers 187.5kW at 100rpm. The
maximum fluctuation of energy per revolution is 15%. The speed variation is limited
to 1% either way from the mean diameter of the rim is 2.4m. Design a cast iron
flywheel for the engine. [AU, Nov / Dec - 2008]
4.169) A single cylinder four stroke oil engine develops 20kW at 300rpm. The work
done by the gases during the expansion stroke is 2.3 times the work done on gases
during the compression and work done during the suction and exhaust strokes are
negligible. The speed is to be maintained within ±1%. Determine the mass moment
of inertia. [AU, Nov / Dec - 2011]
4.170) A blanking press turns out 150 blanks per min. E ach operation starts with a peak
torque of 9KNm and gradually reduces to 0 over a 30 of crank rotation of the ram.

The flywheel of the press is mounted in a lay shaft rotating at 500rpm and max.
Permissible overall speed variation is 25rpm. Find the power requirement of the
press and determine the C.S of CI flywheel. Assume suitable data.
4.171) A cast iron flywheel for a blanking press has a mean diameter of 1.5m. The
normal operating speed of 275 rpm slows down to 250 rpm during the punching
operation. The required energy Fluctuation is 6500 joules and the density of the cast
iron is 7000 kg/m3
. Find the area of flywheel rim if the arms and hub provide 7% of
the flywheel effect. [AU, Nov / Dec – 2015]
4.172) Design an overhang crankshaft for the following data maximum load on the
crankpin for max torque position = 50 kN; crank radius = 200 mm; Distance between
crank pin center and nearby bearing center = 300 mm; Allowable stress in bending
= 70 Mpa; Shear = 50 Mpa; Bearing = 7 Mpa
4.173) Design a plain carbon steel center crankshaft for a single acting 4 stroke single
cylinder engine for the following data. Bore = 400 mm, stroke = 600 mm, engine
speed = 200 rpm mean effective pressure = 0.5 N/mm2
, max combustion pressure =
2.5 N/m2
, Weight of flywheel used as a pulley = 50 kN, Total belt pull = 6.5 kN.
4.174) Design a plain carbon steel centre crankshaft for a single acting four stroke,
single cylinder engine for the following data: Piston diameter = 200mm; Stroke =
400mm; Maximum Combustion Pressure = 2N/mm2
; Weight of Flywheel = 15kN;
Total Belt Pull 3N; Length of the Connecting Rod = 900mm. When the crank has
turned through 30 o
from top dead centre, the pressure in the piston is 1N/mm2
and
the torque on the crank is maximum. Any other data for the design may be assumed.
[AU, May / Jun - 2012]
4.175) When the crank turned through 35o
from the top dead center, the pressure on the
piston is 1 N/mm2
and the torque on the crank is maximum. The ratio of the
connecting rod length to the crank radius is 5. Assume any other data required for
the design.
4.176) Design a side (or) overhung crankshaft for a 250 mm * 300 mm gas engine. The
weight of the flywheel is 30 kN and the explosion pressure is 2.1 N/mm2
. The gas
pressure at the maximum torque is 0.9 N/mm2
, when the crank angle is 35o
from IDC.
The connecting rod is 4.5 times the crank radius.
4.177) The connecting rod of a petrol engine is to be designed for the following data.

Piston diameter = 80 mm
Stroke = 120 mm
Weight of reciprocating parts = 15 N
Length of connecting rod = 240 mm
Speed (maximum) = 2800 rpm
Explosion pressure corresponding to 10o
of crank angle is 3 MPa. Factor of safety is
6.If the connecting rod is to be made of 40Crl steel, find the dimension of the I-
section connecting rod. [AU, Nov / Dec - 2010]
4.178) Design a suitable connecting rod for a petrol engine for the following details.
Diameter of the piston = 100mm; weight of the reciprocating parts per cylinder =
20N; connecting rod length = 300mm; Compression ratio = 7:1; Maximum explosion
pressure = 3N/mm2
; Stoke = 140mm; speed of the engine = 2000rpm.
[AU, Nov / Dec - 2012]
4.179) Determine the dimension of an I-section connecting rod for a petrol engine for
the following data. [AU, Nov / Dec –2013, 2016]
Diameter of piston = 110 mm
Mass of the reciprocating parts = 2 kg
Length of the connecting rod from center to center = 325 mm
Stroke length = 150 mm
R.P.M = 1500 with possible over speed of 12500
Compression ratio = 4 : 1
Maximum explosion pressure = 2.5 N/mm2
.
4.180) A connecting rod is required to design for a high speed, four stroke I.C engine.
The following data are available.
Diameter of the piston = 88mm
Mass of the reciprocating parts = 1.6kg
Length of the connecting rod center - center = 300mm
Stroke = 125mm
Rpm (when developing 50kW) = 2200
Possible over speed = 3000 rpm

Compression ratio = 6.8:1
Probable maximum explosion pressure (assumed shortly after centre, at about 3˚) =
3.5N/mm2
. Draw fully dimensional drawings on the connecting rod showing the
provision for the lubrications. [AU, May / Jun - 2012]
4.181) Design a mild steel connecting rod with an I-section for a single cylinder IC
engine from the following data. Diameter of the piston is 0.104 m; weight of
reciprocating parts is 18.2 N; length of connecting rod-center to center is 0.314 m;
stroke length is 0.14 m; speed of the engine is 1500 rpm; Maximum explosion
pressure is 2.28 MPa. Assume that the maximum thrust takes place at TDC during
the explosion stroke. Assume also any missing data. [AU, Nov / Dec –2011]

UNIT – V – BEARINGS
PART – A
5.1) Classify the types of bearings. [AU, May / Jun – 2014, Nov / Dec – 2016]
5.2) What is cooling stress? [AU, April / May – 2010]
5.3) What is meant by hydrodynamic lubrication? [AU, May / Jun – 2016]
5.4) What are journal bearings? Give a classification of these bearings.
5.5) What is meant by journal bearing? [AU, May / Jun – 2013, 2014, 2016]
5.6) What is full journal bearing? [AU, Nov / Dec – 2015]
5.7) For a journal bearing the maximum operating temperature must be less than 80°C.
Why? [AU, Nov / Dec - 2010]
5.8) What is meant by square journal bearing? [AU, Nov / Dec – 2015]
5.9) What are the properties required for bearing material?
5.10) What are the factors to be considered while selecting a type of bearing?
5.11) Write a short note on the lubricants used in sliding contact bearing.
5.12) Differentiate clearly between sliding contact and rolling contact bearing.
[AU, Nov / Dec –2012]
5.13) Define anti friction bearings. [AU, May / Jun - 2012]
5.14) What are anti - friction bearings? [AU, April / May – 2017]
5.15) Give an example for anti-friction bearing. [AU, Nov / Dec – 2015]
5.16) What do you mean by life of an individual bearing? [AU, May / Jun – 2013, 2016]
5.17) What is meant by life of anti-friction bearings?
[AU, Nov / Dec – 2008, 2013, 2016]
5.18) Why ball bearings are called antifriction bearing? [AU, April / May – 2011]
5.19) Write a short note on classifications and different types of antifriction bearings.
[AU, Nov / Dec –2011]
5.20) Name the materials used for sliding contact bearings [AU, April / May – 2011]
5.21) Classify the sliding contact bearings according to the thickness of layer of the
lubrication between the bearing and the journal. [AU, May / Jun - 2012]
5.22) What are the loads to be considered for designing a ball bearing?
5.23) Explain the term dynamic load carrying capacities of rolling contact bearing.
[AU, Nov / Dec –2012]

5.24) What is meant by Sommerfield number?
5.25) What is Sommerfield number? State its importance in the design of journal
bearing? [AU, Apr / May – 2015]
5.26) What is the limitation of Mckee’s equation? [AU, April / May – 2017]
5.27) Define static Capacity of Bearing [AU, Nov / Dec –2014]
5.28) What are the various types of radial ball bearings? [AU, May / Jun - 2012]
5.29) State the advantage of thrust ball bearing. [AU, Nov / Dec - 2009]
5.30) State the disadvantage of thrust ball bearing. [AU, Nov / Dec - 2009]
5.31) What is quill bearing [AU, April / May – 2010]
5.32) What is self-aligning ball bearing? Statue its unique feature.
[AU, Apr / May – 2015]
5.33) What are the advantages of Rolling Contact Bearings over Sliding Contact
Bearings? [AU, May / Jun – 2016]
5.34) List any 4 advantages of rolling contact over sliding contact bearing.
[AU, May / June – 2009]
5.35) What is the situations demand the use of needle roller bearings?
5.36) In what way the backling strength differed from compressive strength?
5.37) What is meant by self-acting bearing?
5.38) Define the term Reliability of a bearing. [AU, Nov / Dec – 2016]
5.39) Write the differences between hydrostatic and hydrodynamic bearing.
5.40) In hydrodynamic bearing, what are factors which influence the formation of
wedge fluid film? [AU, Nov / Dec –2014]
5.41) List the basic assumptions used in the theory of hydrodynamic lubrication.
[AU, Nov / Dec –2011]
5.42) Plot the friction induced in various bearings based on shaft speed.
5.43) What are the essential requirements in an end face seal?
[AU, Nov / Dec –2013, 2016]
PART – B
5.44) List the types of lubrication used in journal bearing and their characteristics.
[AU, May / June – 2009]

5.45) Enumerate the detail steps involved in the selection of bearings from the
manufacturer’s catalogue. [AU, Apr / May – 2015]
5.46) Explain the variation of coefficient of friction with bearings characteristics
number in sliding contact bearings. [AU, April / May – 2017]
5.47) Explain optimum design of hydrodynamic journal bearings.
5.48) Design a journal bearing for a centrifugal pump to the following specifications.
Diameter of the journal = 75 mm
Speed of the journal = 1140 mm
Load on each journal = 11,500 N [AU, Nov / Dec – 2004]
5.49) Design a journal bearing for a centrifugal pump with the following data:
Diameter of the journal = 150 mm
Load on bearing = 40 kN
Speed of journal = 900 rpm.
[AU, Nov / Dec – 2007, 2015, May / Jun – 2014]
5.50) A journal bearing is to be designed for a centrifugal pump for the following data:
Load on the journal = 12kN
Diameter of the journal = 75mm
Speed = 1440 rpm
Atmospheric temperature of the oil = 16 ˚C
Operating temperature of the oil = 60˚C
Absolute viscosity of the oil at 60˚C = 0.23kg/m-s
Give a systematic design of the bearing [AU, May / Jun - 2012]
5.51) Design a full journal bearing for the following specification D = 75mm: W =
3500N; L = 75mm; N = 400rpm. The minimum oil film thickness ho = 0.02mm.
Determine (i) viscosity of oil (ii) coefficient of friction (iii) heat generated (iv)
amount of oil pumped to the bearing (v) Amount of end leakage (vi) temperature rise
in oil
5.52) A 100 mm diameter full journal bearing supports a Radial load of 5000N. The
bearing is 100 mm long and the shaft operates at 400 rpm. Assume permissible

minimum film thickness of 0.025mm and diametral clearance of 0.152mm. Using
Raimondi and Boyd curves, determine a) viscosity of a suitable oil b) hgc) hdd)
amount of oil pumped through bearings e) amount of oil to be supplied to bearings
f) temperature rise of the oil flowing through the bearings ho = 0.025 C = diametral
clearance = 0.152 mm
5.53) A full journal bearing of 50mm diameter and 100 mm long has a bearing pressure
of 1.4 N/mm2
. The speed of the journal is 900 rpm and the ratio of journal diameter
to the diametral clearance is 1000. The bearing is lubricated with oil whose absolute
viscosity at the operating temperature of 75 0
C may be taken as 0.011 kg/ms. The
room temperature is 350
C. Find the i) amount of artificial cooling required and ii)
mass of lubricating oil required, if the difference between the outlet and inlet
temperature of the oil is 10o
C. Take specific heat of the oil as 1850 J/kg/C o
.
[AU, Nov / Dec – 2012]
5.54) A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure
1.4N/mm2
. The speed of the journal is 900 rpm and the ratio of journal diameter to
the diametral clearance is 1000. The bearing is lubricated with oil whose absolute
viscosity of the operating temperature is 35o
C. Find the
(i) The amount of artificial cooling required and
(ii) The mass of lubricating oil required if the difference between the outlet and
inlet temperature of oil is 10o
C. Take specific heat of oil as 1850 J/kg/o
C.
[AU, Nov / Dec – 2008, 2015]
5.55) Design a journal bearing for a centrifugal pump from the following data: Load on
the journal = 20 kN, speed of the journal = 900 rpm, type of oil is SAE 10 for which
the absolute viscosity at 55°
C = 0.017 N/m-s; ambient temperature of oil = 15.5°
C,
maximum bearing pressure for the pump = 1.5 N/mm2
. Calculate the mass of the
lubricating oil required for artificial cooling, if the rise of temperature of oil be
limited 10°
C. Heat dissipation co-efficient = 1232 W/m2
/0
C.
[AU, May / June – 2007, 2016, Nov / Dec – 2011, 2013, 2016]
5.56) Design a journal bearing for 12 MW, 1000 rpm steam turbine, which is supported
by two bearings. Take the atmospheric temperature as 16ºC and operating
temperature of oil as 60°C. Assume viscosity of oil as 23 Ns/m2
.
[AU, May / Jun – 2013, 2016, Nov / Dec – 2016]

5.57) A 50 mm diameter journal bearing rotates at 1500 rpm, L/D = 1, radial
clearance is 0.05 mm, minimum film thickness = 0.01 mm. Calculate the maximum
radial load that the journal bearing can carry and still operate under hydrodynamic
condition. For this load, calculate power lost in friction and increase in the oil
temperature. Assume Hg = Hd. Absolute viscosity = 20*103
Pas, Sp. Gravity of oil
0.8, Sp. Heat of oil 2.1 kJ/kg°C. [AU, Nov / Dec –2014]
5.58) A wall bracket supports a Plummer block for 80mm diameter shaft. The length
of bearing is 120 mm. The cap of bearing is fastened by means of four bolts, two on
each side of the shaft. The cap is to withstand a load of 16.5 KN. The distance
between the center line of the bolt is 150 mm. Determine the thickness of the bearing
cap and the diameter of the bolts. Assume safe stress in tension for the material of
the cap, which is cast- iron, as 15 MPa and for bolts as 35 MPa. Also check the
deflection of the bearing cap taking E = 110 KN/mm2
.
5.59) A footstep bearing supports a shaft of 150 mm diameter, which is counter board
at the end with a hole diameter of 50mm. If the bearing pressure is limited to 0.8
N/mm2
and the speed is 100rpm, find the i) load to be supported ii) power lost in
friction and iii) heat generated at the bearing . Assume co-efficient of friction =
0.015.
5.60) Design a journal bearing for a 49.9 mm diameter journal. It is ground and
hardened and is rotating at 1500 rpm in a bearing of diameter and length both 50
mm. The inlet temperature of oil 65°C. Determine max radial load that the journal
can carry and power loss. [AU, April / May – 2017]
5.61) Select a suitable deep groove ball bearing for supporting a radial load of 10KN
and an axial load of 3 KN for a life of 4000 hrs at 800 rpm. Select from series 63.
Calculate the expected life of the selected bearing.
[AU, Nov / Dec - 2012, May / Jun – 2013, 2016]
5.62) The following data is given for a 3600
hydrodynamic bearing.
Journal diameter = 100 mm
Bearing length = 100 mm
Radial load = 50 KN

Journal speed = 1440 rpm
Radial clearance = 0.12 mm
Viscosity of the lubricant = 16 cP.
Calculate the i) minimum film thickness ii) co-efficient of friction iii) power
lost in friction
5.63) Explain in detail rolling contact bearing failure – causes and remedies.
[AU, Nov / Dec - 2009]
5.64) A ball bearing is operated on work cycle consisting of three parts – a Radial load
of 3000 N at 1440 rpm for one quarter cycle, a Radial load of 5000 N at 720 rpm for
one half cycle, and Radial load of 2500 N at 1440 rpm for the remaining cycle. The
expected life of bearing is 10,000 hr. Calculate the dynamic load carrying capacity
of the bearing. [AU, Nov / Dec - 2009]
5.65) The load on the journal bearing is 150 kN due to turbine shaft of 300 mm diameter
running at 1800 rpm. Determine the following.
(i) Length of the bearing if the allowable bearing pressure is 1.6 N/mm2
and
(ii)Amount of heat to be removed by the lubricant per minute if the bearing
temperature is 60o
C and viscosity of the oil at 60o
C is 0.02 kg/m-s and the
bearing clearance is 0.25 mm. [AU, May / June – 2009, Nov / Dec –2011]
5.66) Design a journal bearing to support a load of 5000N at 720rpm using a hardened
steel journal and a bronze bracket babbit bearing. The bearing is lubricated by oil
rings. Room temp. is 25 C and oil temp. is 82C. Assume viscosity of oil as
25Centipoise.
5.67) Design a journal bearing for a centrifugal pump from the following data: Load on
the journal = 20000 N; Speed of the journal = 900 rpm; Type of oil is SAE 10, for
which the absolute viscosity at 55° C = 0.017kg/m-s; Ambient temperature of oil=
15.5° C; Maximum bearing pressure for the pump = 1.5 N/mm2
.
5.68) A journal bearing 150mm diameter and 300mm long carries a radial load of 9kN
at 1220rpm. The diametral clearance is 0.075mm. If 6kW is being lost in friction.
What is the viscosity of the oil used at given operating temperature?
[AU, Nov / Dec - 2012]

5.69) The load on a 100mm full hydrodynamic journal bearing is 9000N. Speed of the
journal is 320rpm. Let l/d = 1, C/d = .0011. The operating temp. is 65C and minimum
oil film thickness is 0.022m. Find (i) Select an oil (ii) Frictional loss (iii) Oil flow
(iv) Amount of leakage (v) Temperature rise of oil (vi) Max. oil pressure
5.70) Load on a hydrodynamic full journal bearing is 30kN. The diameter and speed of
the shaft are 150mm and 1200rpm respectively. Diametral clearance 0.2mm.
Sommerfield number is 0.631. L/D ration 1:1. Calculate temperature rise in oil,
quantity of oil, heat generated and type of oil required. [AU, Apr / May – 2015]
5.71) A bearing for an axial flow compressor is used to support a Radial load of 2500N
and a thrust load of 1500N. The service required for the bearing is 5years at the rate
of 40hours per week. The speed of the shaft is 1000rpm. Select suitable ball bearing
for the purpose. The diameter of shaft is 50mm.
5.72) Design a suitable ball bearing for an axial flow compressor to carry a radial load
of 2.5 kN and a thrust load of 1.3 kN. The service imposes a light shock with shock
factor 1.5 and bearing will be in use for 35 hours per week for 4 years. The speed of
shaft is 900 rpm and diameter of shaft is 45 mm. Assume X = 0.56 and Y= 1.4.
[AU, Nov / Dec – 2015]
5.73) A ball bearing is subjected to a radial load of 10 kN and a thrust load of 5 kN. The
inner ring rotates at 1000 rpm. The average life is to be 5000 hours. What basic load
rating must be used to select a bearing for this purpose? Take Fa / C0 = 0.5 and assume
service factor 1.5. [AU, April / May – 2017]
5.74) Select a bearing for a 40 mm diameter shaft rotates at 400 rpm. Due to bevel gear
mounted on the shaft, the bearing will have to withstand a 5000 N radial load and a
3000 N thrust load. The life of the bearing expected to be at least 1000 hrs.
[AU, May / Jun – 2014]
5.75) Select a deep groove ball bearing it carry a radial load of 5kN and thrust load of
1.5kN. The diameter of the shaft is 130mm and rotates at 2500rpm. The expected
life of the bearing is 20,000 hrs.
5.76) Select a deep groove ball bearing from series 63 to take a radial load of 4kN and
axial load of 2kN. The speed of shaft 1000rpm. Life of bearing 10,000 hrs.

5.77) The Radial reaction on a bearing is 9000N. It also carries a thrust of 5000N. The
speed of the shaft is 1000rpm. The outer ring is stationary. Expected average life of
bearing is about 25000hrs. The load on bearing is smooth, the service is 8hrs/day.
(i) Select suitable roller bearing
(ii)What is the rated 90% life of selected bearing?
(iii) Compute the probability of selected bearing surviving 25000hrs
5.78) The Radial reaction on a bearing is 8000N. It also carries a thrust of 5000N. The
shaft diameter is 140mm and it rotates at 1700rpm. The outer ring is stationary. The
load on bearing is smooth, the service is 8hrs/day for a life of 17000hrs.
(i) Select suitable deep groove ball bearing
(ii) What is the rated 90% life of selected bearing?
(iii) For b = 1.34, compute the probability of the selected bearing surviving
17000 hours [AU, April / May – 2017]
5.79) Select a suitable ball bearing to support the overhang counter shaft. The diameter
of the shaft is 60mm and speed 1000rpm. The bearing are to have 99% of reliability
corresponding to life of 10,000hrs. The baring is subjected to equivalent radial load
of 4kN and axial load of 2kN
5.80) A ball bearing subjected to a radial load of 5 kN is expected to have a life of 8000
hours at 1450 r.p.m, with a reliability of 99%. Calculate the dynamic load capacity
of the bearing so that it can be selected from the manufacturer's catalogue based on
a reliability of 90%. [AU, Nov / Dec – 2016]
5.81) A 6207 Radial bearing is to operate in the following cycle:
Radial load of 4500N at 150rpm for 30% of time
The inner ring rotates, loads are steady, what is the expected average life of
the bearing.
5.82) The Radial load on a roller bearing varies as follows. A load of 50KN is acting
20% of time at 500rpm and a load of 40KN is acting 50% of time at 600rpm. In the
remaining time, the load is varying from 40KN to 10KN linearly at 700rpm. Select

a roller bearing from N22 series for a life of at least 4000hrs. The operating
temperature is 175C.
5.83) A single row deep ball bearing is subjected to a Radial force of 8kN and the thrust
force of 3kN. The shaft rotates at 1200rpm. The expected life of the bearing is
20,000hr. The minimum acceptable diameter of the shaft is 75mm. Select a suitable
ball bearing [AU, April / May – 2010]
5.84) A single row deep groove ball bearing No.6002 is subjected to an axial thrust load
of 1000N and a Radial load of 2200N. Find the expected life that 50% of the bearings
will complete under this condition [AU, Nov / Dec - 2010]
5.85) Select a single row deep groove ball bearing for a radial load of 4000 N and an
axial load of 5000 N, operating at a speed of 1600 rpm for an average life of 5 years
at 10 hours per day. Assume uniform and steady load. [AU, Nov / Dec – 2015]
5.86) Select a single row deep groove ball bearing for a radial load of 4000 N and an
axial load of 5000 N, operating at a speed of 1600 rpm for an average life of 5 years
at 10 hours per day. Assume uniform and steady load. Take 300 working days per
year. [AU, May / Jun – 2016]
5.87) A ball bearing is operated on both cycle consisting of three parts. A radial load of
3kN at 1440rpm for one fourth of cycle. A radial load of 5kN at 720rpm for half
cycle, a radial load of 2500N at 1440rpm for the remaining cycle. The life of the
bearing is 10,000hrs. Calculate the dynamic load carrying capacity and also find the
specification of the bearing.
5.88) For 6307 ball bearing , the load varies as follows:
S.NO
RADIAL
LOAD
(N)
AXIAL
LOAD
(N)
CYCLE TIME
RATIO
SPEED
(Rpm)
1 6300 3000 0.5 400
2 7500 - 0.3 650
3 4000 1000 0.2 900
The inner ring rotates, loads are steady, what is the expected average life of the
bearing.

5.89) Find the rated load of a deep groove ball bearing for the following load cycle.
S.NO RADIAL LOAD (N) AXIAL LOAD (N) % OF TIME
1 3000 1000 15
2 3500 1000 20
3 3500 10 30
4 500 2000 35
Also find the 90% life of ball bearing if bearing used is 6207 with dynamic
capacity 19620 N [AU, Nov / Dec –2014]
5.90) In a deep groove ball bearing (6306) is to operate at 1600rpm and carries 8KN
Radial load and 6KN thrust load. Determine the rating life of the bearing.
5.91) Select a suitable ball bearing for a drilling machine spindle of diameter 40mm
rotating at 300rpm. It is subjected to a Radial load of 2000N and axial load of 1000N.
It is to work for 45 hours a week for one year.
5.92) A 30BC03 deep groove ball bearing is to operate at 1600rpm and carries 8KN
Radial load and 6KN thrust load. The bearing is subjected to light shock load.
Determine the rating life of the bearing.
5.93) Select a suitable deep groove ball bearing for the following data, Radial load of
7500N and axial load of 4500N. Speed is 2000rpm. L10 = 4.9*108
r
5.94) Select a suitable Conrad – type deep groove ball bearings for the following data,
the radial load 7500N and axial load is 4500N, the shaft speed is 2000rpm, the L10
life required is 4.9*108
revolutions; the inner of the bearing rotates.
[AU, May / Jun – 2012]
5.95) Select a deep groove ball bearing for a radial load of 4000N and axial load of
5000N operating at a speed of 160rpm for an average life of 5 years at 10 hours per
day. Assume uniform and steady load. [AU, Nov / Dec - 2012]
5.96) In a deep groove ball bearing, diameter is 40mm, Speed is 400rpm, Radial load
of 5000N and axial load of 3000N, Life is 1000hrs. Calculate Dynamic capacity of
the bearing

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