Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 5th Sem New 2151907 Design Of Machine Elements Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (NEW) EXAMINATION ? WINTER 2018
Subject Code:2151907 Date:20/11/2018
Subject Name:Design of Machine Elements
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Explain series of preferred number 03
(b) State the advantages of chain drive over belt drive 04
(c) Explain important design considerations for casting products 07
Q.2 (a) Explain leaf spring with neat sketch 03
(b) Explain springs in series and parallel connections with sketch 04
(c) A spring having outer diameter of coil as 72 mm, deflects for 50 mm
at the maximum load of 700 N. Calculate the wire diameter and
number of turns for the spring if the shear stress is 300 MPa and
modulus of rigidity 84 KN/mm2 . Take spring index of 8
07
OR
(c) Design a helical compression spring with plain ends made out of
bronze for operating load range of 100 N to 150 N. The deflection of
the spring is 6 mm and spring index = 9. The allowable shear stress for
spring is 300 MPa and modulus of rigidity is 80 KN/mm
2
. Determine
(1) Diameter of spring wire (2) Mean coil diameter (3) Total number
of turns (4) Stiffness of spring
07
Q.3 (a) Explain effect of slip and creep on belt drive 03
(b) List advantages and disadvantages of chain drive 04
(c) The centre distance between two shafts is 4 m for a flat belt drive. The
thickness of the belt is 10 mm. The driving pulley having 350 mm
diameter is rotating with 1800 RPM. Driven pulley is rotating with 600
RPM. Considering slip of 5% determine outer diameter of driven
pulley and belt length for (1) open belt drive (2) crossed belt drive
07
OR
Q.3 (a) Explain effect of initial tension on belt drive 03
(b) Explain working of (1) Compound belt drive (2) Fast and loose pulley
belt drive with neat sketch
04
(c) Design a V-belt drive from the given data. Motor power = 3.75 KW,
Belt Width = 17 mm, Speed of motor = 1440 RPM, Belt thickness =
11 mm, Speed reduction = 4, Belt area = 140 mm
2
, Density of belt=
1.5 x 10
(-5)
N/mm
3
, Endurance limit for belt is 10N/mm
2
07
Q.4 (a) What is pre-stressing? Why is it required in pressure vessels 03
(b) A thin spherical shell with a storage capacity of 5000 litres is subjected
to internal pressure of 1.5 N/mm
2
. Determine the thickness of the shell.
Take allowable stress for shell material = 75N/mm
2
consider joint
efficiency 75%.
04
(c) Derive the equation of hoop stress and longitudinal stress for thin
cylinder
07
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (NEW) EXAMINATION ? WINTER 2018
Subject Code:2151907 Date:20/11/2018
Subject Name:Design of Machine Elements
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Explain series of preferred number 03
(b) State the advantages of chain drive over belt drive 04
(c) Explain important design considerations for casting products 07
Q.2 (a) Explain leaf spring with neat sketch 03
(b) Explain springs in series and parallel connections with sketch 04
(c) A spring having outer diameter of coil as 72 mm, deflects for 50 mm
at the maximum load of 700 N. Calculate the wire diameter and
number of turns for the spring if the shear stress is 300 MPa and
modulus of rigidity 84 KN/mm2 . Take spring index of 8
07
OR
(c) Design a helical compression spring with plain ends made out of
bronze for operating load range of 100 N to 150 N. The deflection of
the spring is 6 mm and spring index = 9. The allowable shear stress for
spring is 300 MPa and modulus of rigidity is 80 KN/mm
2
. Determine
(1) Diameter of spring wire (2) Mean coil diameter (3) Total number
of turns (4) Stiffness of spring
07
Q.3 (a) Explain effect of slip and creep on belt drive 03
(b) List advantages and disadvantages of chain drive 04
(c) The centre distance between two shafts is 4 m for a flat belt drive. The
thickness of the belt is 10 mm. The driving pulley having 350 mm
diameter is rotating with 1800 RPM. Driven pulley is rotating with 600
RPM. Considering slip of 5% determine outer diameter of driven
pulley and belt length for (1) open belt drive (2) crossed belt drive
07
OR
Q.3 (a) Explain effect of initial tension on belt drive 03
(b) Explain working of (1) Compound belt drive (2) Fast and loose pulley
belt drive with neat sketch
04
(c) Design a V-belt drive from the given data. Motor power = 3.75 KW,
Belt Width = 17 mm, Speed of motor = 1440 RPM, Belt thickness =
11 mm, Speed reduction = 4, Belt area = 140 mm
2
, Density of belt=
1.5 x 10
(-5)
N/mm
3
, Endurance limit for belt is 10N/mm
2
07
Q.4 (a) What is pre-stressing? Why is it required in pressure vessels 03
(b) A thin spherical shell with a storage capacity of 5000 litres is subjected
to internal pressure of 1.5 N/mm
2
. Determine the thickness of the shell.
Take allowable stress for shell material = 75N/mm
2
consider joint
efficiency 75%.
04
(c) Derive the equation of hoop stress and longitudinal stress for thin
cylinder
07
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2
OR
Q.4 (a)
Explain any two types of end covers used in pressure vessels
03
(b) An accumulator is required to store 175 litres of water at a pressure of
25 N/mm
2
. Assume the length of the stroke to be 3 meter. Determine
(1) The diameter of the Ram (2) The internal diameter of the cylinder
(3) The thickness of the cylinder if the allowable stress of the cylinder
made of cast iron is 60 N/mm
2
04
(c) Determine the maximum load using Soderberg equation simply
supported 50 mm diameter beam centrally loaded as P to 3P N. The
ultimate strength is 690 MPa, yield strength = 400 MPa, factor of
safety = 1.5. Use size correction factor of 0.85 and surface finish factor
of 0.9. consider length as 600mm.
mm.07
Q.5 (a) Find out the number of R5 basic series from 1 to 10 03
(b) What is stress concentration? Discuss any two methods of reducing it 04
(c) Explain Goodman line design criteria for fluctuating stresses 07
OR
Q.5 (a) It is required to standardize 11 shafts from 100 to 1000 mm diameter.
Specify their diameters.
03
(b) Explain fluctuating stress in detail 04
(c) Explain S-N diagram for steels with neat sketch 07
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This post was last modified on 20 February 2020