B.Sc. Construction Management : Strength of Materials Annamalai University December 2014 Question Paper

Annamalai University december 2014 question paper
B.Sc. DEGREE EXAMINATION December 2014
(CONSTRUCTION MANAGEMENT)
(FOURTH SEMESTER)
420: STRENGTH OF MATERIALS-II
Time: Three hours Maximum: 75 marks
Answer ONE FULL question from each UNIT (5 × 15 = 75)
UNIT-I
1. The principal tensile stress at a point across two perpendicular plane are
80MN/m2 and 40MN/m2. Find the normal, tangential and resultant
stresses and its obliquity on a plane at 20° with the major principal plane.
(OR)
2. Explain strain energy theory.
UNIT-II
3. What must be the length of a 5mm diameter aluminium wire so that it can
be twisted through one complete revolution without exceeding shearing
stress of 42MN/m2? Take C=27GN/m2.
(OR)
4. A hollow shaft subjected to a torque of 40KNm and a bending moment of
30KNm. The internal diameter of the shaft is one –half the external
diameter. If the maximum shear stress is not to exceed 80MN/m2 find the
diameter of the shaft.
UNIT-III
5. Explain Euler’s theorem for long column?
(OR)
6. Calculate the safe compression load on a hollow cast iron column (one end
rigidly fixed and the other hinged) of 150mm external diameter, 100mm
internal diameter and 10m length. Use Euler’s formula with a factor of
safety of 5, E=95GN/m2
UNIT-IV
7. A cylindrical chimney 2m high of uniform circular section is of 5m external
diameter and 3m internal diameter. The intensity of horizontal wind
pressure is 1.5 KN/m2. Find max and min normal stress. Take γ=20KN/m2,
K=2/3.
(OR)
8. A angle 80×80×10mm having Ixx=Iyy=87.36×10–8m4. It is used as a freely
2
supported beam with one leg vertical. The bending moment m the vertical
plane yy the mid-section of the beam deflects in the direction AA′ at 30°15′
to the vertical.
(i) Calculate the second moment-of area of the section about its
principal axis.
(ii) What is the bending stress at the corner B if the bending moment is
1.5 KNm.
UNIT-V
9. A ring D made of round steel bar 25 mm diameter and the mean of the ring
is 150mm. Calculate the maximum tensile and compressive stresses in the
material of the ring of it is subjected to a pull of 10KN.
(OR)
10. Find the forces in the members of the truss shown in figure.
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