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DR. BABASAHEB AMBEDKAR TECHNOLOGICAL UNIVERSITY, LONERE
Semester Examination MAY - 2019
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Branch: SY Mechanical Engineering
Sem.: IV
Subject with Subject Code: SOM (BTMEC403)
Date: 20-05-2019
Marks: 60
Time: 3 Hr.
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Instructions to the Students
1
2
3
4
. Each question carries 12 marks.
. Attempt any five questions of the following.
. If some part or parameter is noticed to be missing, you may appropriately
assume it and should mention it clearly
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(Marks)
Q.1. a) Define the following terms
i) Young’s Modulus
ii) Modulus of Rigidity
iii) Poisson’s ratio
iv) Factor of safety
v) Hook’s law
(05)
b) Two brass rods and one steel rod together support a load as shown in Fig
2
below. If the stresses in brass and steel are not to exceed 60 N/mm and
2 5
20N/mm , find the safe load that can be supported .Take E for steel = 2 x 10
2 5 2
1
N/mm and for brass = 1 x 10 N/mm . The cross sectional area of steed rod is
1
2
2
500 mm and of each brass rod is 1000 mm .
(07)
OR
b) A steel rod of 3 cm diameter is enclosed centrally in a hollow copper tube of
external diameter 5 cm and internal diameter of 4 cm. The composite bar is then
subjected to an axial pull of 45000 N. If the length of each bar is equal to
1
5 cm. Determine:
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i) The stresses in the rod and tube.
ii) Load carried by each bar.
(07)
Q.2. a) Prove that stress induced in a body when the load is applied with the impact
is given by
where P = Load applied with impact, A = Cross-sectional area of the body,
h = height through which load falls, L= Length of the body, and
E = Modulus of elasticity.
(06)
OR
2
a) The maximum stress produced by a pull in a bar of length 1 m is 150 N/mm .
The area of cross-sections and length are shown in Fig. Calculate the strain
5
2
energy stored in the bar if E = 2 x 10 N/mm .
(06)
2
2
b) The stresses at a point in a bar are 200 N/mm (tensile) and 100 N/mm
compressive). Determine the resultant stress in magnitude and direction on a
plane inclined at 60° to the axis of the major stress. Also determine the
maximum intensity of shear stress in the material at the point. (06)
(
Q.3. a) A hollow rectangular section is having external size 500 mm x 450 mm
internal size 400 mm x 350 mm. It carries a vertical load of 100 kN at outer
edge of the column on X-axis. Calculate maximum and minimum intensities of
stresses in the section. Assume 500 mm side horizontal.
(06)
b) Draw the shear force and bending moment (B.M.) diagram for a simply
supported beam of length 9 m and carrying a uniformly distributed load of
1
0 kN/m for a distance of 6 m from the left end. Also calculate the maximum
B.M. on the section.
(06)
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Q.4.
(12)
Q.5. a)
(
05)
05)
OR
a)
b)
(
(07)
Q.6. a)
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J = Polar moment of inertia,
τ = Max. Shear stress,
C = Modulus rigidity,
θ = Angle of twist, and
L = Length of the shaft.
(06)
b) A hollow shaft, having an inside diameter 60% of its outer diameter, is to
replace a solid shaft transmitting the same power at the same speed. Calculate
the percentage saving in material, if the material to be used is also the same.
(06)
OR
b) A solid round bar 4 m long and 5 cm in diameter was found to extend
.6 mm under a tensile load of 50 kN. This bar is used as a strut with both ends
hinged. Determine the buckling load for the bar and also the safe load taking
factor of safety as 4. (06)
4
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