Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 5th Semester (Fifth Semester) 2015-2016 Machine Design I Eme 501 Nme 501 Question Paper
(Following Paper ID and Roll No. to be filled in your
Answer Book)
Ron NOEEEEEEEEE]:
B.Tech.
(SEM. V) THEORY EXAMINATION, 2015-1 6
MACHINE DESIGN-I
Time : 3 hours] [MaximunMarks : 100
Note :Attempt all sections (A, B and C)
? Section-A
l. Attempt all parts. All sections carry equal marks. Write
answer of each section in short. (10X2=20)
(a) List the factors that in?uence the selection of
materials for speci?c application.
(b) What is ergonomic consideration in design?
(c) Why Wahl?s correction factor is used in spring
design?
( 1) P.T.O.
((1) Why preferred numbers are important in machine
design? '
(e) Wh'y fatigue failure of materials is important while
designing machine part?
(0 Why ef?ciency of screw jack should not be more
than 50%?
(g) Why most of the components are designed for
in?nite life?
(h) Why repeated stresses are crucial in ductile
materials?
(i) List components designed for ?nite life. 4
(i) What is rated life of a system?
Section-B
Note: Attempt any five questions from this section.
lOXS=507
Q2. (a) What are preferred numbers in design?
(b) A manufacturer is interested to start a business with
six models of machines ranging from 7.5 kW -75
kW. Specify power capacity of six models.
. (2) NME-SOI
!
(a)
(b)
(a)
(b)
l
3!? w
E .0
NCO;
I
i
What do you understand by i) FE320 ii) FeE 200
iii) 40C8.
How Will you designate the following varieties of
steel i) carbon= 30-40%, Si=0.8-0.9%, Mn=0.7-
0.9%, Cr=3.5-4.5%. ii) C=45-55%, Cr=l8%, .
Va=21%
A rectangular bar made of carbon steel 40C8 is
subjected to a tensile load as shown in ?g 1.0.
Calculate the max stress in the baI with ?llet radius
being 3mm (aal dimensions in mm).
20:}SkN
A cylindrical bar made of Fe620 is ssubjected to
combined bending moment and to torsional
moment of lOkN-m & 30kN-m respectively.
Determine the diameter of the bar for a factors of
safely of 2.0
I (3) ETC
(8)
' (b)
(a)
0))
A stepped shaft, stepped from 40 mm to 30 mm is
subjected to a torsional moment of 100 N-m. If
the stress concentration at ?llet is 2.3, what is the
max stress in the shaft?
A machine components is subjected to a bending,
stress varying from 300 MPa to -150 MPa.
Calculate the minimum required ultimate strength,
if the factor of saftey is 1.5
Differentiate between collar friction and thread
friction.
v
r
Design a triple riveted butt joint for a boileif of
1 .2m inner diameter operating at a steam presspre
l
of 1.5mPa.
Design a protected type ?ange coupling to transmit 135
kW @ 120 rpm. Assume 40C8 as material forjall
' components. Assume any missing data. ;
? (4)
A helical spring made of oil tempered carbon steel
subjected to varying load from 600N to 1000N. Design
the spring for a spring index of 6 and a factors of safety
of 1.5. The material of the spring may be selected as
music wire.
Design the screw of a screw jack to li? a load of 95 kN
through a height of 250 mm. verify the design using
principal stresses and buckling failure.
? Section-C
Attempt any ?0 questions from this section.
10.
(2 X l 5=3 0)
(a) Dist guish between shaft axle and spindle.
(b) Design a sha? to transmit 25 kW @ 200 rpm
carying a central load of 900 N and is simply
supported between bearings l .0 m apan. Allowable
tensile and shear stresses for material are 56 & 42
MP3 respectively.
i (5) P.T.0.
ll.
12.
A hot rolled steel sha? is subj ected to a van'able bending
moment of +440 Nm to -220 Nm and a torsional
moment of 330 Nm to 110 Nm. Shaft is of no varying
cross-section. Determine the required shaft diameter.
If the material has ultimate tensile and yield strength of .
550 N/mm2 and 440 N/mm2 with a factor of safety of
1.5.
A cylindrical steel sha? of ultimate and yield strength
of 580 & 360 N/mm2 respectively and a cylindrical
corrected endurance strength of 200 N/mm2 is subj ected
to a combined bending & torsional moments -30 MP3
,to +30 MPa and -15 MPa to +30MPa respectively.
Calculate the factors of safety.
, (6) NME-501 / 18900
This post was last modified on 29 January 2020