PTU Punjab Technical University B-Tech May 2019 Question Papers 4th Semester Aerospace Engineering
Total No. of Pages : 03
Total No. of Questions : 09
B.Tech.(ANE) (Sem.?4)
AIRCRAFT STRUCTURES ? I
Subject Code : ANE-206
M.Code : 60514
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
SECTION?A
1.
Write briefly :
a) Derive the relations between stress and strain in a plane stress problem.
b) State the principle of superposition.
c) What is Prandtl stress function solution?
d) Derive an expression for the strain energy of a bar subjected to uniaxial tensile force.
e) What is Shear lag?
f) What is meant by a doubly redundant structure?
g) State the different types of loads acting on aircraft structural components.
h) Write down an expression for the shear flow in an open section beam subjected to
shear forces Sx and Sy.
i) Explain the term : `Margin of Safety'
j) What are principal planes and principal stresses?
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SECTION?B
2.
A point in a strained material is subjected to a tensile stress of 120 N/mm2 and a
compressive stress of 80 N/mm2 acting at right angles to each other. Find the normal
stress, tangential stress and the resultant stress on a plane inclined at an angle of 30? with
the compressive stress.
3.
A circular section bar of radius R is subjected to equal and opposite torque T at each of
its free ends. Determine ; (a) rate of twist and (b) stress distribution.
4.
Calculate the rotation of point 1 of the contilever beam in Fig. 1. Using the principle of
complementary virtual work. Neglect shear deflection.
y
2
3EI
3
3
EI3
1
x
L
L
Fig.1
5.
Sketch a typical V-H diagram and briefly explain (a) stall regions (b) method of plotting
various segments of the diagram (c) Red-line speed of the air plane and (d) Significance
of maneuver point and corner velocity.
6.
Describe the different types of fitting failures with the help of suitable sketches.
SECTION?C
7.
A cantilever of length L and depth 2h is in a state of plane stress. The cantilever is of unit
thickness, is rigidily supported at the end x = L and is loaded as shown in fig. 2.
Show that the stress function :
= A x3 + B x2 y + cy3 = D (5x2 y 3 ? y5)
is valid for the beam and evaluate the constants A, B, C and D in terms of q and h.
q/unit area
h
x
h
L
y
Fig.2
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8.
A structure is shown in Fig. 3. Assuming the member to be of uniform cross-section
throughout find :
a) Strain energy stored by the structure and hence
b) Determine the vertical deflection of end A.
L
B
A
x
y
W
h
C
Fig.3
9.
Write notes on :
a) Maneuver Loads
b) Direct stress distribution due to bending.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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This post was last modified on 04 November 2019