Answer ALL Questions
PART A – (10 x 2 = 20 Marks)
2. Define Strain.
3. State Hooke’ s law.
4. Define factor of safety.
5. State tensile stress and tensile
strain).
6. State volumetric strain.
7. Define modulus of elasticity
8. Define modulus of rigidity
9. State Bulk modulus.
10. Define
poisson’s ratio.
PART - B (5 x 16=80
Marks)
Answer all questions
1) An axial pull of 40 KN is
acting on a bar consisting of three section of length 300mm, 250mm, and 200mm
and of diameters 20mm, 40mm, and 50mm respectively. Find the stresses in each
section and total extension of the bar. Take E=2 x 105N/mm2.
2) Calculate the force p3
and change in length for the following Fig . Take E= 200 GN/m2; p1
=120 KN; p2 =220kN; and p4 =160 KN.
3) A compound bar of length
500 mm consists of a strip of aluminium 40 mm wide x 15 mm thick and a strip of
steel 40 mm wide x 10 mm thick rigidly joined at ends. If the bar is subjected
to a load of 50 KN find the stress developed in each material and the extension
of the bar . Take modulus of elasticity of aluminium and steel as 1.1 x 105
N/mm2 and 2.1 x 105N/mm2.
4) Determine the change in
length , breadth and thickness of a steel bar 4 m long 30 mm wide and 20 mm
thick, when subjected to an axial pull of 120 kN in the direction of its
length. Take E = 200 Gpa and Poisson’s ratio = 0.3.
5) A rod is made of brass,
copper and aluminium as shown in fig. is held between two rigid supports at A
and D. Calculate the stresses developed in each material when the temperature
of the system is raised by 400C . Take Es=2.1 x 105N/mm2.
Ec=1.1 x 105N/mm2 Ea=0.7 x 105N/mm2.
á½±s=12 x 10-6/0C;. á½±c=17
x 10-6/0C ; á½±a =21 x 10-6/0C..
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