B.E-B.E Aeronautical Engineering Solid Mechanics(Manonmaniam Sundaranar University (MSU)-2010)
Friday, 23 August 2013 02:36Duraimani
(Established under section 3 of UGC Act,1956)
Course & Branch :B.E - AERO
Title of the Paper :Solid Mechanics Max. Marks :80
Sub. Code :526305 Time : 3 Hours
Date :05/05/2010 Session :AN
PART - A (10 x 2 = 20)
Answer ALL the Questions
1. Draw stress strain diagram for ductile material.
2. Define Thermal stress.
3. Write any 2 assumptions made in simple Bending.
4. Define simply supported beam.
5. What do you mean by close coiled helical spring?
6. Define Slenderness ratio.
7. Define Principal Stresses.
8. Write the stresses developed in thin walled Pressure vessels.
9. State Castigliano’s Theorem.
10. Define strain energy.
PART – B (5 x 12 = 60)
Answer All the Questions
11. Derive a relation between the modulus of elasticity and the modulus of rigidity.
(or)
12. A rod of steel is 20 metres long at a temperature of 20°C.
Find the free Expansion of the rod when the temperature is raised to 65°C. Find the temperature stress produced
(a) when the expansion of the rod is prevented
(b) when the rod is permitted to expand by 5.8mm
Take E=2 x 105N/mm2 and Coefficient of linear expansion a = 12 x 10-6 per°C.
13. A timber beam is 160mm wide and 300mm deep and is simply supported on a span of 5 metres. It carries a uniformly distributed load of 3000 N per metre run over the whole span and three equal concentrated loads W Newtons each placed at mid span and quarter span points. If the stress in timber is not to exceed 8N/mm2 find the maximum value of W.
(or)
14. A beam of span L metres simply supported at the ends, carries a central load W. The beam section has an overall depth of 290mm with horizontal flanges each 150mm x 20mm and a vertical web 250mm x 10mm. If the maximum shear stress is to be 45N/mm2 when the maximum bending stress is 150N/mm2, calculate the value of the centrally applied load W and the span L.
15. A solid steel shaft has to transmit 75kW at 200rpm. Taking allowable shear stress as 70N/mm2, find the suitable diameter of the shaft, if the maximum torque transmitted in each revolution exceeds the mean by 30%. Also find the outer diameter of a hollow shaft to replace the solid shaft if the diameter ratio is 0.7.
(or)
16. A hollow cylindrical cast iron column is 4 metres long, both end being fixed. Design the column to carry an axial load of 250kN. Use Rankine’s formula and adopt a factor of safety of 5. The internal diameter may be taken as 0.80 times the external diameter. Take Fc = 550N/mm2 and a = 1/1600.
17. At a certain section of a shaft 80mm in diameter there is a bending moment of 3.5 kNm and a twisting moment of 5 kNm. Find the maximum direct stress induced in the section and specify the position of the plane on which it acts. Taking Poisson’s ratio as 0.28, find what stress acting alone can produce the same maximum strain.
(or)
18. At a certain point in a strained material the principal stresses are 100 N/mm2 and 40N/mm2 both tensile. Find the normal, tangential and resultant stresses across a plane through the point at 48° to the major principal plane, using Mohr’s circle of stress.
19. A horizontal girder of steel having uniform section is 14 metres long and is simply supported as its ends. It carries concentrated loads of 120 kN and 80kN at two points 3 metres and 4.5 metres from the two ends respectively. Moment of Inertia I for the section of the girder is 16 x 108 mm4. And Es = 210kN/mm2. Calculate the deflections of the girder at points under the two loads. Find also the maximum deflection. (Use Macaulay’s method)
(or)
20. A simply supported beam of span 1 carries a point load W at mid span. Find the strain energy stored by the beam and calculate the central deflection.
| Earning: ₹ 0.20/- |
