Reg No.:

C192020 Pages: 3

Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

THIRD SEMESTER B.TECH DEGREE EXAMINATION(R&S), DECEMBER 2019

Course Code: CE201
Course Name: MECHANICS OF SOLIDS

Max. Marks: 100 Duration: 3 Hours

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PART A
Answer any two full questions, each carries 15 marks. Marks

Differentiate between(i) Normal stress and shear stress (ii) Young’s modulus and (3)
Rigidity modulus (iii) Poisson’s ratio and volumetric strain

A steel bar ABCD consists of three sections: AB 15 of 20 mm diameter and 200 (8)
mm long, BC is 25 mm square and 400 mm long and CD is of 12 mm diameter

and 200 mm long. The bar is subjected to an axial compressive load which
induces a stress of 30 MN/m* on the largest cross section. Determine total
decrease in length of the bar when the load is applied. Assume E = 210 GPa

Find the Poisson’s ratio and bulk modulus of a material whose modulus of (4)
elasticity is 200 GPa and modulus of rigidity is 80 GPa. A 2 m long rod of 40 mm
diameter made with the same material is stretched by 2.5 mm under some axial

load. Find the lateral contraction.

A linearly tapered bar with circular cross section is subjected to an axial load. (5)
Derive an expression for the change of length.

A brass bar of 25 mm diameter is enclosed in a steel tube of 25 mm internal (8)
diameter and 50 mm external diameter. Both of them are 1൩ long at room
temperature and fastened rigidly to each other at the ends. If the room temperature

is 20°C, find to what temperature the assembly should be heated so as to generate

a compressive stress of 48.7 MN/m’ in brass. What is the stress in steel at this
temperature? Assume E=200 0017; 100 GN/m*; a=11.6 x 10 5/0: ‏مه‎
‎=18.7 x10 6

Obtain the expressions for strain energy stored in a prismatic bar due to axial load. (2)
Draw the stress strain curve of mild steel and mark the salient points (6)
A vertically suspended bar with collar at lower end has 30 mm diameter. If a (9)
tensile load of 7500 N is applied gradually it produces an extension of 0.3 mm.

Determine the height from which this load should be dropped to produce a

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