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- Mechanics of Solids - MOS
- 2016
- PYQ
**Biju Patnaik University of Technology Rourkela Odisha - BPUT**- Civil Engineering
- B.Tech
**9227 Views**- 562 Offline Downloads
- Uploaded 2 years ago

http://www.bputonline.com Registration No: 109 Total Number of Pages: 03 B.TECH PCI3I001 3rd Semester Regular Examination 2016-17 MECHANICS OF SOLIDS BRANCH: CIVIL Time: 3 Hours 109 Max Marks: 100 Q.CODE: Y495 Answer Part-A which is compulsory and any four from Part-B. The figures in the right hand margin indicate marks. b) c) d) e) 109 f) g) h) 109 i) j) Q2 109 109 a) b) c) d) e) f) g) h) i) j) http://www.bputonline.com 109 (2 x 10) (2 x 10) 1 a) 109 Part – A (Answer all the questions) Answer the following questions: A steel bar of 40 mm diameter is subjected to an axial compressive load of 250 kN. If the length of the bar is 2 m and E = 200 GPa, the elongation of the bar will be ____________. A 100 mm diameter steel bar free to expand is heated from 15°C to 40°C. It develops ________________ stress. Poisson’s ratio is the ratio between ______________ and ________________ Section modulus is the ratio between ___________ and ___________ A concentrated load of P acts on a simply supported beam of span L at a distance L/2 from the left support. The bending moment at the point of application of the load is _________ A simply supported beam of span length 6m and 50mm diameter carries a uniformly distributed load of 1.0 kN/m. The maximum value of bending moment is _______________ The point· of contraflexure is a point where________________ changes sign. For a circular shaft of diameter d subjected to torque T, the maximum value of the shear stress is ______________ . The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to internal hydrostatic pressure is_______________. The expression for the crippling load for a column of length „l‟ with one end fixed and other end free is _______________. Answer the following questions: Define the term factor of safety and its importance. What is Complementary shear stresses. What are the types of stresses developed in thin cylinders subjected to internal pressure? What are principal planes? What is Mohr’s stress circle ? Explain its significance. When Macaulay’s method is preferred? State the relation between shear force and bending moment. What is a Strut ? How does it differ from a column ? Write the equation for strain energy stored in a shaft due to torsion. What is the value of shear stress at the centre of a circular shaft under torsion? Page Q1

http://www.bputonline.com Part – B (Answer any four questions) 109 Q3 a) Draw stress - strain curve for a mild steel rod subjected to tension and explain about the salient points on it. (7) b) A cylindrical vessel, whose ends are closed by means of rigid flange plates, is made up of steel plate 3 mm thick. The length and internal diameter of the vessel are 50 cm and 25 cm respectively. Determine the longitudinal and hoop stresses in the cylindrical shell due to an internal fluid pressure of 3 N/mm2. Also calculate the increase in length, diameter and volume of vessel. Take E = 2×105 N/mm2 and poisson’s ratio =0.3. (8) Q4 a) Direct tensile stresses of 120 MPa and 70 MPa act on a body on mutually perpendicular planes. What is the magnitude of shearing stress that can be applied so that the major principal stress at the point does not exceed 135 MPa? Determine the value of minor principal stress and the maximum shear stress. (10) b) The principal tensile stresses at a point across two perpendicular planes are 100 MPa and 50 MPa. Find the normal and tangential stresses and the resultant stress and its obliquity on a plane at 200 with the major principal plane. (5) 109 109 Q5 A loaded beam is as shown below. Draw its S.F and B.M diagram. (15) Q6 A cantilever of length 2.5m is loaded with an udl of 10 kN/m over a length 1.5m from the fixed end. Determine the slope and deflection at the free end. Determine the slope and deflection at the free end of the cantilever. Given I = 9500cm4, E = 210 GN / m2 Using Moment area method. (15) 109 109 109 http://www.bputonline.com 109 (8) (7) 2 109 Derive the relation Page M E , Symbols has their usual meaning. y I R b) A simply supported beam of span 4m carries a udl of 6kN/m over the entire span. If the maximum allowable stress due to bending is restricted to 150 N/mm2, determine the cross sectional dimensions if the section is; (i) Rectangular with depth twice the breadth (ii) Solid circular section (iii) Hollow circular section having a diameter ratio of 0.6 Q7 a)

http://www.bputonline.com 109 109 Q8 a) A solid shaft transmits 100 kW at 60 rpm. Determine the diameter of the shaft if the shear stress is not to exceed 75MPa. If the shaft is replaced by a hollow shaft whose internal diameter is 0.6 times external diameter, while length, material and the maximum shear stress are the same, find the percentage saving in weight. b) Two shafts are made of same material and transmits the same power. The first rotates at 50 rpm while the second rotates at 1000 rpm. Determine the ratio of diameters of the two shafts for the same maximum shear stress in each shaft. (7) Q9 a) Derive the Euler crippling load for a vertical strut with both ends are hinged, acted upon by an axial load P. b) Using Euler’s formula, determine the critical stress for a strut of slenderness ratio 80 under the condition of (i) both the ends are hinged and (ii) both the ends are fixed. Take E=210Ga. If the slenderness ratio is 120 what will be the critical stress in both the cases. (8) (8) (7) 109 109 109 109 Page 3 109 http://www.bputonline.com 109

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