Hall Ticket No: Question Paper Code: A3108
VARDHAMAN COLLEGE OF ENGINEERING
(AUTONOMOUS) B. Tech IV Semester Regular Examinations, May 2018
(Regulations: VCE-R15) STRENGTH OF MATERIALS-II
(Civil Engineering) Date: 15 May, 2018 FN Time: 3 hours Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
Unit I
1. Derive the torsional equation for a circular shaft subjected to torque. 5M
A close coiled cylindrical spiral spring of circular section has coils with a 75mm mean
diameter. When loaded with an axial load of 250N, it is found to extend 160mm and
when subjected to a twisting couple of 3Nm there is an angular rotation of 60 degrees.
Determine the Poisson's ratio for the material.
10M
2. Distinguish between close coiled springs and open coiled springs also list any five
functions of the spring.
7M
A closely coiled helical spring of 100mm mean diameter is made up of 10mm diameter
rod and has 20 turns. The spring carries an axial load of 200N. Determine the shearing
stress. Take the value of G=8.4x104MPa, determine the deflection, also calculate stiffness
of the spring.
8M
Unit II
3. Obtain an expression for Euler's buckling load of a column with both ends hinged. 8M
A column of 5m length is fixed at both ends. The column is of rectangular cross-section
20cm x 10cm. Determine the Euler's load on the column if E=200GN/m².
7M
4. State the assumptions made in Euler's analysis. 7M
A 1.5m long column has a circular cross-section of 5cm diameter. One of the ends of the
column is fixed in direction and position and the other end is free. Taking the factor of
safety as calculate the safe load using:
i. Rankin Gordon formulae- take yield stress=56kN/cm2 and =1/1600 for pinned
ends
ii. Euler's formula, E=12MN/cm2
8M
Unit III
5. What are retaining walls? Explain Rankine's assumptions made for the theory of earth
pressure.
5M
A square chimney 30m high has a flue opening of size 1.5mx1.5m, find the minimum
width required at the base for no tension if the masonry weighs 20kN/m3 and the wind
pressure is 1.5kN/m2. The permissible stress in masonry is 1MPa.
10M
6. State the conditions of stability in case of dam. 5M
A masonry retaining wall has the trapezoidal section with top width 1.5m, bottom width
4m and height 6m. The angle of repose of the retained material is 300 the masonry
weighs 20kN/m3 and the earth has a density of 18kN/m3. Find the maximum and
minimum stress intensities at the base.
10M
Unit IV
7. Write the computational procedure for the deflection of the beam due to unsymmetrical
bending.
5M
A channel section has flanges 100x10mm and web 160x10mm, determine the shear
center of the channel.
10M
8. A cast iron beam is of T-section with top flange 100x20mm and bottom flange 20x80mm. The
beam is simply supported on a span of 8m. The beam carries a UDL of 1.5kN/m length on the
entire span. Determine the maximum tensile and compressive stresses.
15M
Cont…2
2
Unit V
9.
Obtain an expression for the strains in a thin cylindrical shell due to internal pressure.
7M
A cylindrical vessel closed with plane ends is made of a 4mm thin steel plate. Its diameter is 25mm and length is 75mm. It is subjected to an internal fluid pressure of 300N/cm². Calculate the longitudinal and hoop stresses in the shell plate. Also, calculate changes in diameter, length and volume of the cylinder. Take E=210GN/m² and Poisson's ratio 0.3.
8M
10.
Explain Lame's theorem relating to thick cylinder and state assumptions made in this theory.
7M
The diameters of a thick cylindrical vessel are 16cm and 24cm. calculate the maximum and minimum hoop stresses due to an internal pressure of 600kN/cm². Sketch the distribution of circumferential and radial stresses across the section.
8M