Maharashtra State Board of Technical Education 2009 Diploma Fabrication Engineering Design of Fabricated Structural Element - Question Paper

Sample ques. Paper
Course Name : Fabrication Technology & Erection Engineering
Course Code : FE
Semester : Sixth
Subject : Design of Fabricated Structural Element
Marks : 80 Time: three Hrs.
Instruction:
1. All ques. are compulsory.
2. Illustrate your answers with neat sketches wherever necessary.
3. Figures to the right indicate full marks.
4. presume suitable data if necessary.
5. Preferably, write the answers in sequential order.
Q.1 Attempt any 4 of the following: 16 Marks
a) Write general procedure of machine design.
b) elaborate various kinds of sunk keys. Draw a neat sketch of any 1 sunk key & provide
its application.
c) discuss with neat sketch the bolts of uniform strength.
d) explain 4 advantages of screwed joint.
e) describe stress concentration with neat sketches discuss how to decrease stress
concentration.
f) describe - i) Ductility & malleability
ii) Toughness & stiffness.
Q.2 Attempt any 3 of the following: 12 Marks
a) Draw stress – strain diagram for M.S showing salient points on it.
b) A shaft is needed to transmit 1MW power at 240rpm. The shaft must not twist more
than one in a length of 1m. If modules of rigidity for the materials of the shaft is
80KN/mm2. obtain the diameter of the shaft.
c) A plate 80mm wide & 10mm thick is joined with a different plate by a single transverse
& double parallel fillet welds. The maximum tensile & shear stresses are 70MPa &
50MPa respectively. obtain the length of every parallel fillet if the joint is subjected to
static load of 56KN.
d) Draw a neat sketch for
9237
i) Single riveted single strap butt joint
ii) Double riveted lap joint (chain riveted)
Q.3 Attempt any 3 of the following: 12 Marks
a) Sketch any 4 basic weld symbols with their sectional representation.
b) discuss with neat sketch caulking & fullering.
c) A bracket as show in fig.1 ; supports a load of 30 KN. Determine the size of the bolts;
if the maximum allowable tensile stress in the bolt materials is 60MPa. The distance
are a; L1-80mm; L2=250mm & L =500mm.
FIG. 1
d) Determine the forces in all member of truss show in fig NO.2
FIG. 2
Q.4 Attempt any 2 of the following: 16 Marks
a) Design a cast iron flange coupling to transmit 15 KW at 900rpm. From an electric
motor to a compressor. The service factor may be presumed as 1.35 the subsequent
permissible stresses may be used. Shear stress for shaft; bolts & keys material is 40
MPa. Crushing stress for bolt & key -80MPa.
b) Design a circular flanged pipe joint. presume suitable material & stress values on your
own.
c) Determine forces in all member of truss shown in fig.NO.3
FIG. 3
Q.5 Attempt any 3 of the following: 12 Marks
a) With neat sketch discuss any 2 pipe joints.
b) describe perfect frame & deficient frame & state the relation ranging from the number of
joints& number of member in a perfect frame.
c) elaborate various kinds of locking devices in screwed joint? discuss application of
any 1 locking device with neat sketch.
d) Write any 4 advantages of welded joints.
Q.6 Attempt any 2 of the following: 12 Marks
a) A 200 X 150 X 10mm angle is to be welded to a steel plate by fillet welds as shown in
fig. 4. If the angle is subjected to a static load of 200KN; obtain the length of weld at the
top & bottom. The allowable shear stress for static loading may be taken as 75MPa.
(REFER FIG.NO.4)
FIG. 4
b) A steam engine cylinder has an effective diameter of 350mm & maximum steam
pressure acting on the cylinder cover is 1.25 N/mm2. compute number & size of studs
needed to fix the cylinder cover, assuming the permissible stress in the stud as
33MPa, Take thickness of cylinder wall(t=10)
c) Double reverted lap joint is made ranging from 15mm thick plates. The rivet diameter &
pitch are 25mm & 75mm respectively. if the ultimate stresses are 400 MPa in tension
320 MPa in shear & 640 Mpa in crushing . obtain the joint force per pitch which will
rupture.

Earning:   Approval pending.