Biju Patnaik University of Technology 2008 B.Tech Mechanical Engineering Mechanics of Materials -II - Question Paper

Total number of printed pages – 4 B.Tech
CPME 6305

Sixth Semester Examination- 2008
MECHANICS OF MATERIALS –II
Full Marks- 70
Time :- three Hrs
ans to ques. no. one is compulsory and any 5 from the rest.
The figures in the right hand margin indicate marks.

1.Answer the subsequent questions: 10X2=20
(a) State castgliano’s theorem.
(b) State Maxwell’s theorem of reciprocity.
(c) Define notch sensitivity.
(d) Explain stress optic legal regulations.
(e) Define gage factor of an electric resistance strain gage.
(f) Mention the relative orientation of the polarizer, analyzer & quarter wave plates for dark field arrangement of polariscope.
(g) Explain the difference ranging from isocline and isochromatic fringes.
(h) What do you mean by birefringence?
(i) Mention 4 materials with their composition used for making resistance strain gages.
(j) Distinguish ranging from completely reversible and repeated load cycle.

2 A steel tube of 200 mm external diameter is to be shrunk onto a different steel tube
of 60mm internal diameter. The diameter at the junction after shrinking is
120mm.Before shrinking on, the difference of diameters at the junction is
0.08mm.Calculate the radial pressure at the junction & the hoop stresses
developed in the 2 tubes after shrinking on. Take young’s modulus of steel as
2.0*10^5Mpa. 10

3 A curved bar has a rectangular cross-section breadth = 60mm & depth = 80mm.
The beam is subjected to pure bending .find the ratio of the numerical values of maximum &minimum bending stress along the depth of the part. 10

4 A cantilever beam of square cross-section b*b is bent by a couple M. The couple M acts in a plane
passing through the centroidal axis of the beam &making an angle Ø with the vertical passing
through the centroidal axis. What curve will be defined by the end of the beam? When the angle
Ø varies from 0 to2?? For what Value of Ø the bending stress will be maximum? 10

5 A cantilever beam of length L & constant flexural rigidity EI is loaded by a concentrated load W acting at the mid span. Determine by energy method the deflection & slope at the loading point considering only flexure. 10

6 At certain point on a steel machine part, measurement with an electric rectangular strain rosette, indicate that €0?= 0.0005,€45?=+0.0003,€90?=+0.0004. Assuming that young’s modulus of steel, E=2.0*10^5Mpa & poission’s ratio v=0.3. obtain the principal stresses at the point investigated. 10

7 What do you mean by the endurance limit of a material? define the detail experimental procedure for determining the fatigue strength of a material. 10

8 At a point in a strained material, on plane BC there are normal &shear stresses of 560Mpa & 140 Mpa respectively. On a plane AC, perpendicular to plane BC, there are normal &sheer stresses of 280Mpa&140Mpa respectively as shown in figure-1 beneath.
Determining the following:
(i) Principal stress & location of the planes on which they act. 5
(ii) Maximum shear stress & the plane on which it acts. 5

I
|
| ?280 Mpa
| | 140 Mpa
| V
|
|
________________________|
E C
?140 Mpa
| 560 Mpa
V

Earning:   Approval pending.