SKR Engineering College 2007 B.E Mechanical Engineering STRENGTH OF MATERIALS - Question Paper

SKR ENGINEERING COLLEGE

Mechanical Engineering Department

Model exam

STRENGTH OF MATERIALS

Date: 19/04/2007
Time: three hrs maximum Marks: 100

ans ALL ques.

Part A – (10 x two =20)
1. Define shear force and bending moment.
2. Draw the bending stress distribution in a T-section due to bending.
3. What are the 2 conditions to be satisfied in the design of a circular shaft?
4. State moment area theorems.
5. Define the term stiffness, spring index of a spring.
6. A rectangular R.C. simply supported beam of a span three m and cross part 200mm x 350 mm carries a point load of 100 KN at its midspan. obtain the maximum slope and deflection of the beam if E = two x 104.
7. What is meant equivalent length of column?
8. what are the assumptions made in the theory of simple bending
9. What are the different advantage of hollow shaft over a solid shaft?
10. Draw the BMD for cantilever beam subjected couple M at the free end.
Part- B (5 x 16 =80)
11. Draw the shear force and bending moment diagrams for the bam shown in
Fig 1.and also indicate the points of contra flexure if any






800 N 2000 N 1000N

three KN two KN/m four KN





0.5 m 1.5 m two m 1.5 m 0.5m

Fig 2
Or

12. Draw the shear force and bending moment diagrams for the bam shown in fig 2

13. A hollow shaft with diameter ratio 3/8 is needed to transmit 500 KW at 100 rpm, the maximum torque being 20% greater than the mean. The maximum shear stress is not exceeding 60 MPa and the twist in a length of three m is not to exceed 1.4 degree. compute the minimum diameters needed for the shaft. C=84 GPa

Or
14 Solid shaft is subjected to a torque of 100Nm. obtain the necessary shaft diameter if the allowable shear stress is 100 MPa and the allowable twist is three degree per 10 m length of the shaft. Take C=1 x 10 five N / mm 2

15 Cantilever of length 2a is carrying a load of W at the free end, and a different load of W at its centre. Determine by moment area method, the slope and deflection of the cantilever at the free end.

Or
16 For the beam shown in fig three obtain deflection at C, D and maximum deflection. EI=360000KNm2






17 a) derive a relation for deflection of a closely coiled helical spring subjected to an axial downward load W

b) A quarter elliptic leaf spring 60 cm long is made of steel plates of width 10 times the thickness. The spring is to carry a load of three KN and the end deflection is limited to five cm. the bending stress of the plates must not exceed 3000 N /mm2. obtain suitable of the size and number of plates to be used. Take E= two x 10 five N/mm2
or

18) compare the crippling loads provided by Rankin’s and Euler’s formulae for tubular strut 2.25m long having outer and inner diameters of 37.5 mm and 32.5 mm loaded through pin-joint at both ends.

19) A cast iron water main 12 m long ,of 500 mm inside diameter and 25 mm wall thickness runs full of water and is supported at its ends. compute the maximum stress in the metal if density of cast iron is 7200 kg /m3 and that of water is 1000 kg/m3.
Or
20) An overhanging beam ABC six m long is supported at A and B such that AB=4 m. it is loaded with point load of 10 KN at the end C. if E=200GPa and I=12 x 10-6 m4 determine a)deflection at the point load b)maximum deflection

Earning:   Approval pending.