Pondicherry University 2007-3rd Sem B.Tech ..Bio - medical engg. syllabus -2008 - Question Paper

(b) How do you determine the slope and deflection of beam using conjugate beam method? (7)

(or)

6. (a) determine the slope at the 2 supports and maximum deflection of a simply supported beam carrying concentrated load W at mid span using conjugate beam method. (8)

(b) determine the slope and deflection at the free end of a cantilever carrying a uniformly distributed load over the entire span using Moment area method. (7)


UNIT – 4

7.(a) A hollow shaft having external diameter twice its internal diameter transmits 600Kw at 150 r.p.m .determine the external
diameter of the shaft if the shear stress is not to exceed 65 N/mm^2 and the twist in a length of 3m should not exceed 1.4degrees.assume that the maximum torque is 1.2 tomes the mean torque and the modulus of rigidity = 1*10^5 n/mm^2

(b)a close coiled helical spring deflects 10mm under an axial load of 100N at a shear stress of 90N/mm^2 . the coil mean diameter is 10times the wire diameter .the Youngs modulus of the material of the wire E=80 Kn/mm^2.determine

(i) the diameter
(ii) the length of the wire (7)

8.(a) A laminated spring 0.9m long is made up of plates every 5cm wide and one cm thick. The bending stress in the plate is limited to 120 n/mm^2.the young’s modulus of material E=2*10^5 N/mm^2.determine

(i) the number of plates needed to enable the spring to carry a central point load of 2.65Kn.


(ii) the deflection under the load. (8)


(b) A shaft part 100 mm in diameter is subjected to a bending moment of 4000 Nm and a torque of 6000Nm.the poisson’s ratio is 0.25 .determine

(i)the maximum direct stress induced on the part and the position of the plane on which it acts

(ii) the stress which acts alone and causes the identical maximum strain. (7)


UNIT - 5

9. (a) elaborate the assumptions and limitations of euler’s theory? (8)

(b) A hollow cast iron strut having 150mm external diameter and 100 mm internal diameter is 8m long is subjected to axial compressive load.assuming a factor of safety of 5,yield stress = 550 n/mm^2 and rankaine’s constant a=1/500,determine the safe load using rankine’s formula (7)

(or)

10 (a) a bar of length when used as a simply supported beam of 30Kn/m over the whole span deflects 15mm at mid span .determine the crippling load when it is used as a coloumn and


(i) both ends are pin jointed.
(ii) One end is fixed and other end is hinged
(iii) Both ends are fixed (8)


(b) A circular cast iron column of diameter 250mm carries a vertical load of 600KN at a distance of 35mm from the axis.Determine the extreme values of the stresses induced in the part. (7)

Earning:   Approval pending.