R5220103 Strength Of Materials Ii

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Code No: R5220103

II B.Tech. II Semester(R05) Supplimentary Examinations, April/May 2009 STRENGTH OF MATERIALS-II (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. A piece of material is subjected to tensile stress of 70N/mm2 and 30 N/mm2 at right angles to each other. Find the normal, tangential and resultant stresses on a plane the normal to which makes an angle of 450 with the greater stress. Sketch the direction of these stresses neatly. [16] 2. (a) What are springs and where they are used? (b) How many types of springs are there? Explain the behaviour of each type. (c) Give examples of the use of various types of springs?

[6+6+4]

3. An R.S.Tee-section, 150mm wide × 75mm deep, thickness of flange 9mm, thickness of web 8.4mm, is used as a strut, 3 metre 4 long, ends hinged.Calculate the safe axial load by Rankines formula, using a factor of safety of 3. Rankines constants, f c = 315N/mm2 ; a = 1/ 7500. [16] 4. (a) What are laterally loaded struts. (b) A horizontal strut of length L, having ends, carries an axial compressive load P and lateral u.d.l. of intensity w per unit length through out span. Derive expressions for max. Values of deflection, B.M. and stress. [4+12] 5. A cylindrical chimney shaft of a hollow circular section, 2.50 metres external diameter, 1 metre internal diameter, is 30 metres high. If the horizontal intensity of wind pressure varies as X 2/3 where X is the vertical height above the ground, calculate the overturning moment at the base due to the force of wind pressure, taking the coefficient of wind-resistance as 0.6. Given that the horizontal intensity of wind pressure at a height of 20 metres is 1KN/m2 . If the weight of masonry is 22.5KN/m3 , calculate the extreme intensities of stress at the base. [16] 6. A 240 mm × 120 mm steel beam of I-section is simply supported over a span of 6m and carries two equal concentrated loads at points 2 m from each end. The properties of the section are Ixx = 6012.32 × 104 mm4 , Iyy = 452.48 × 104 mm4 . (a) Determine the magnitude of the loads when the plane of the loads is vertical through YY. The permissible stress is 150 N/mm2 in compression and tension. (b) Determine the degree of inclination of the plane of these loads to the vertical principal plane YY that will result in 20 percent greater bending stress than permitted under (a). [16] 7. A semi circular beam is supported on three equally spaced columns. Derive expressions for max.B.M. and max. Twisting moment by first obtaining the general expressions. [16] 8. (a) Find the forces in the members of the cantilever truss loaded as shown in figure 1. by the method of joints.

Figure 1: (b) Illustrate the types of supports conditions with the help of sketches. ?????

[12+4]

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Code No: R5220103

II B.Tech. II Semester(R05) Supplementary Examinations, April/May 2009 STRENGTH OF MATERIALS-II (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Applying max. strain energy theory find the dia of a steel bar subjected to an axial pull of 10 kN along with a transverse S.F of 5 kN. Take the elastic limit in tension as 240 MPa and F.O.S. = 3. [16] 2. (a) What is the difference between a closely coiled and open coiled helical springs? (b) Derive the formula to find the deflection of a closely coiled helical spring subjected to an axial load.[6+10] 3. An R.S.Tee-section, 150mm wide × 75mm deep, thickness of flange 9mm, thickness of web 8.4mm, is used as a strut, 3 metre 4 long, ends hinged.Calculate the safe axial load by Rankines formula, using a factor of safety of 3. Rankines constants, f c = 315N/mm2 ; a = 1/ 7500. [16] 4. (a) What do you understand by “Beam-columns”? (b) A horizontal strut of length L, having hinged ends, carries an axial compressive load P, and central vertical load W. Derive expression for max values of deflection, B.M. and stress. [4+12] 5. A cylindrical chimney shaft of a hollow circular section, 2.50 metres external diameter, 1 metre internal diameter, is 30 metres high. If the horizontal intensity of wind pressure varies as X 2/3 where X is the vertical height above the ground, calculate the overturning moment at the base due to the force of wind pressure, taking the coefficient of wind-resistance as 0.6. Given that the horizontal intensity of wind pressure at a height of 20 metres is 1KN/m2 . If the weight of masonry is 22.5KN/m3 , calculate the extreme intensities of stress at the base. [16] 6. A simply supported beam of rectangular section (60 × 80)mm carries a load of 2KN at the center of 4m span. The load line is inclined at 30 to the vertical passing through the c.g. of section. Determine the max deflection and stress at the top corner. (E = 210KN/mm2 ). [16] 7. (a) Where do you use beams curved in plan? (b) A circular beam is loaded uniformly and supported an symmetrically placed Columns. If W is the load per unit length, R, the radius, derive expressions for S.F B.M and tossional moment at a point P, at an angle φ from one support. [4+12] 8. A simply-supported, pin-jointed, plane wauen girder of equilateral triangles is loaded at the lower panel joints as shown in figure 1. Find the forces in the members CE, DE, EF, DF using the method of sections. [16]

Figure 1:

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Code No: R5220103

II B.Tech. II Semester(R05) Supplementary Examinations, April/May 2009 STRENGTH OF MATERIALS-II (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Using max. strain energy theory, estimate the safe dia. for a mild steel rod to carry an axial pull of 10 kN together with a transverse shear 5 kN and the factor of safety 3. Take the Poissons ratio as 0.3. [16] 2. A solid steel shaft has to transmit 80 H.P. at 200 R.P.M. The max. torque transmitted in each revolution exceeds the mean by 30%. Find a suitable dia. of the shaft if the permissible shear stress is 80N/mm2 . [16] 3. An R.S.Tee-section, 150mm wide × 75mm deep, thickness of flange 9mm, thickness of web 8.4mm, is used as a strut, 3 metre 4 long, ends hinged.Calculate the safe axial load by Rankines formula, using a factor of safety of 3. Rankines constants, f c = 315N/mm2 ; a = 1/ 7500. [16] 4. A horizontal strut 3m long is of-hollow circular section 16cm external dia. And internal dia. 14cm. It carries an end thrust of 300kN along with a u.d.l of 5kN/m. Assuming the ends as hinged and taking the self weight also into account, calculate the max. stress induced in the section (Density = 78.5kN/m3 ). [16] 5. Find the max. and minimum stress intensities at the weakest section of a flat bar 200mm wide and 30mm thick carrying an axial pull of 240kN. A 40mm dia. Hole is punched at a distance of 60mm from the axis of the bar. Sketch the stress distribution. [16] 6. A simply supported beam of rectangular section (60 × 80)mm carries a load of 2KN at the center of 4m span. The load line is inclined at 30 to the vertical passing through the c.g. of section. Determine the max deflection and stress at the top corner. (E = 210KN/mm2 ). [16] 7. (a) Where do you use beams curved in plan? (b) A circular beam is loaded uniformly and supported an symmetrically placed Columns. If W is the load per unit length, R, the radius, derive expressions for S.F B.M and tossional moment at a point P, at an angle φ from one support. [4+12] 8. Using the method of section find out the forces in all the members of the simply-supported pin-jointed plane truss loaded as shown in figure 1. [16]

Figure 1: ?????

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Code No: R5220103

IV B.Tech. II Semester(R05) Supplimentary Examinations, April/May 2009 STRENGTH OF MATERIALS-II (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Draw the Mohr’s circle of stress if a piece of material is subjected to tensile stresses of 80 MPa and 35 MPa on mutually perpendicular planes. Find the plane across which the resultant stress is most inclined to the normal. Find also the magnitude of the resultant stress on this plane. [16] 2. (a) Explain the terms torsional rigidity, torsional section modulus and polar moment of inertia. (b) Derive an expression for the power transmitted by a circular shaft in i. kW ii. H.P.

[9+7]

3. An R.S.Tee-section, 150mm wide × 75mm deep, thickness of flange 9mm, thickness of web 8.4mm, is used as a strut, 3 metre 4 long, ends hinged.Calculate the safe axial load by Rankines formula, using a factor of safety of 3. Rankines constants, f c = 315N/mm2 ; a = 1/ 7500. [16] 4. (a) What do you understand by “Beam-columns”? (b) A horizontal strut of length L, having hinged ends, carries an axial compressive load P, and central vertical load W. Derive expression for max values of deflection, B.M. and stress. [4+12] 5. A horizontal strut 3m long is hinged at both and is of uniform section 40mm wide and 100mm deep. It carries an axial thrust of 100kN together with a u.d.l of 3N/mm. Calculate the max values of deflection, B.M. and stress. (E = 200GN/m2 ). [16] 6. What is Z- Polygon and how is it useful? Obtain the Z- Polygon for a rectangular section and sketch the same. [16] 7. A semi circular beam of radius R, is supported on 3 equally spaced columns. If W is the load per unit length of the beam, derive expressions for B.M and twisting moments at any point P. and hence at supports. [16] 8. Using the method of joints find the forces in all the members of the cantilever truss loaded as shown in figure 1. [16]

Figure 1:

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