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Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
PDDC- SEMESTER-II EXAMINATION SUMMER 2017
Subject Code: X20603 Date:03/06/2017
Subject Name: STRUCTURAL ANALYSIS I
Time: 10:30 AM to 01:00 PM Total Marks: 70
Instructions:
1. Attempt any five questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1

Compare the crippling loads given by Euler's and Rankine's formula for a tubular steel strut 2.3m long having outer and inner diameters 38mm and 33mm respectively, loaded through pin joints at each end. Take the yield stress as 335 N/mm2, the Rankine's constant 1/7500 and E 0.205 X 106 N/mm2. For what length of strut of this cross section does the Euler's formula cease to apply?
07

A masonry retaining wall trapezoidal in section with one face vertical is 1m wide at top and 3m at the base and 8m high. The material retained on the vertical face exerts a lateral pressure varying from zero at top to 25 kN/m2 at the base. If the unit weight of masonry is 21 kN/m2, calculate the maximum and minimum stress intensities induced in the base.
07
Q.2

Find out S.I. and K.I. for the structures as shown in figure-1 and below.
04

Write assumptions made by Euler for deriving critical load for long columns.
03

Analyze the plane frame as shown in Figure-2 below. Draw shear force, bending moment and axial force diagrams.
07
Q.3

For the simply supported beam shown in Figure-3, find (i)slope at each end (ii)deflection at C and D maximum deflection by Macaulay's method. Take E 200 kN/mm2, I 6.5 x 108 mm4.
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Find out θB, θC yB, yC for the beam shown in Figure by Moment area method. Take E 2 x 105 N/mm2, I 5 x 108 mm4.
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Q.4

A suspension bridge cable hangs between two points A and B separated horizontally by 120m and with A 20 m above B. The lowest point in the cable is 4m below B. the cable supports a stiffening girder which is hinged vertically below B and lowest point in the cable. Find the position and magnitude of the largest bending moment which a point load of 10 kN can induce in the girder together with the position of load.
07

Four wheel loads of 8 and 5 kN cross a girder of 20 m span, from left to right followed by and u.d.l. of 4 kN/m and 4 m long with the 6 kN load leading. The spacing between the loads in the same order are 3m, 2m and 2m. The head of the u.d.l. is at 2m from the last 5 kN load. Using influence lines, calculate the S.F. and B.M. at a section 8m from the left support when the 4 kN is at centre of the span.
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Q.5

A 450 kW power has to be transmitted at 100 R.P.M. Find the necessary diameter of solid circular shaft, the necessary diameter of circular section, the inside diameter being ¾ of the external diameter. Allowable shear stress 75 N/mm2 and the density of material 77 kN/m3.
07

A load of 200 N falls through a height of 35 mm on to a collar rigidly attached to the lower end of the vertical bar 2 m long having 25 mm radius. The upper end of the bar is fixed. Find maximum instantaneous stress induced in the bar elongation in the bar strain energy stored in the bar. Take E 200 N/mm2.
07
Q.6

A closed cylindrical vessel of length 3 diameter 600 mm and thickness 10 mm
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is subjected to internal pressure of 1.4 N/mm2. Calculate longitudinal stress, hoop
stress, change in length and change in diameter. Take Poisson's Ratio 0.20 and
E 205 GPa.
Define Core of a section Proof resilience Thin cylinder Strut
Modulus of resilience Eccentricity Strain Energy
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Q.7 Derive equation for longitudinal and hoop stress for thin cylindrical shell subjected
to internal pressure
07
The stiffness of a close collide helical spring is 2 N/mm of compression under a
max load of 70 N. The maximum shearing stress produced in wire of spring is
120 N/mm2. The solid length of spring (when the coils are touching) is 60 mm.
Find diameter of wire mean diameter of coil and number of coils
required.
07

Q.2 ii gg Fuuirrgee.---111 aaannnddd
Q.2 Fig.-2 Q.3 Fig.-3 Q.3 Fig.-4