Download PTU B.Tech 2020 March Aero 6th Sem ASPE 311 Vibration And Structural Dynamics Question Paper

Download PTU (I.K. Gujral Punjab Technical University Jalandhar (IKGPTU) ) BE/BTech Aero (Aerospace-Engg) 2020 March 6th Sem ASPE 311 Vibration And Structural Dynamics Previous Question Paper

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Roll No. Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(Aerospace Engg.) (2012 Onwards) (Sem.?6)
VIBRATION AND STRUCTURAL DYNAMICS
Subject Code : ASPE-311
M.Code : 72456
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1. SECTION-A is COMPULSORY consisting of TEN questions carrying TWO marks
each.
2. SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3. SECTION-C contains THREE questions carrying TEN marks each and students
have to attempt any TWO questions.

SECTION-A
1. Distinguish between the following :
(a) Simple pendulum and compound pendulum
(b) Internal and external sources of excitation
(c) Discrete and continuous systems
(d) Damped and un-damped systems
(e) Single degree of freedom and two degree of freedom systems
(f) Derive the equivalent spring constant for two springs in series.
(g) Over-damping and under-damping
(h) Free and forced vibration
(i) Principle modes and normal modes vibration
(j) Whirling of shaft with and without air damping
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1 | M - 7 2 4 5 6 ( S 2 ) - 1 9 7 7
Roll No. Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(Aerospace Engg.) (2012 Onwards) (Sem.?6)
VIBRATION AND STRUCTURAL DYNAMICS
Subject Code : ASPE-311
M.Code : 72456
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1. SECTION-A is COMPULSORY consisting of TEN questions carrying TWO marks
each.
2. SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3. SECTION-C contains THREE questions carrying TEN marks each and students
have to attempt any TWO questions.

SECTION-A
1. Distinguish between the following :
(a) Simple pendulum and compound pendulum
(b) Internal and external sources of excitation
(c) Discrete and continuous systems
(d) Damped and un-damped systems
(e) Single degree of freedom and two degree of freedom systems
(f) Derive the equivalent spring constant for two springs in series.
(g) Over-damping and under-damping
(h) Free and forced vibration
(i) Principle modes and normal modes vibration
(j) Whirling of shaft with and without air damping
2 | M - 7 2 4 5 6 ( S 2 ) - 1 9 7 7
SECTION-B
2. What are vibration absorbers? Explain the working principle of a centrifugal pendulum
vibration absorber with the help of a neat sketch.
3. For damped free vibration system, derive the equation for amplitude for over-damped and
critically damped system.
4. An Instrument has a natural frequency of 15 Hz. It can stand a maximum acceleration of
10 m/s
2
. Find the maximum displacement amplitude.
5. A 25 kg mass is resting on a spring of 5 kN/m stiffness and a dashpot of 150 N-s/m
damping coefficient in parallel. If a velocity of 0.1 m/s is given to the mass at rest
position. What will be its displacement from the equilibrium position at the end of first
second?
6. Add the following harmonic motions analytically :
x
1
= 4 cos ( ?t + 15?); x
2
= 6 sin ( ?t + 60?)

SECTION-C
7. A vibrating system having mass of 1 kg is suspended by a spring of stiffness 1100 N/m
and it is put to harmonic excitation of 12 N. Assuming viscous damping, determine
(a) The resonant frequency 2
(b) The phase angle at resonance 2
(c) The amplitude at resonance 2
(d) The frequency corresponding to the peak amplitude and 2
(e) Damping frequency. Take C = 40 N-sec/m. 2
8. Write short notes on the following :
(a) Holzer?s method. 3
(b) Euler?s equation for beams 3
(c) Vibration measuring instruments 4
9. A uniform string is tightly stretched between x = 0 and x = l and is plucked at x = l/4,
through a distance h and then released from rest. Find its subsequent displacement. 10
NOTE : Disclosure of identity by writing mobile number or making passing request on any
page of Answer sheet will lead to UMC case against the Student.

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