Review_Ch1-Fundamental_of_Vibration.pdf

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Mechanical Vibrations

Chapter 1:Fundamental of Vibration

Dr. Azma Putra

Faculty of Mechanical Engineering

Department of Structure and Materials

Semester II/2012-2013

REVIEW

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 2

Review: Fundamental of VibrationReview: Fundamental of Vibration

Which statement below is not correct about vibration?

a. Periodic motion around equilibrium position

b. Static displacement above an equilibrium position

c. Oscillatory motion around an equilibrium position

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 3

Review: Fundamental of Vibration

In 10 Hz, starting from A, how many times does an object oscillate around

the equilibrium position in one second?

a. 10 times to B and 10 times back to A

b. 5 times to B and 5 times back to A

A

B

equilibrium line

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 4

Review: Fundamental of Vibration

What is the operating frequency of a machine having normal speed of

600 RPM?

a. 600 Hz

b. 60 Hz

c. 10 Hz

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 5

Review: Fundamental of Vibration

Frequency 10 Hz is the same as 62.8 radian/s.

a. TRUE

b. FALSE

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 6

Review: Fundamental of Vibration

If a sensor measures maximum displacement of 5 mm at 1 Hz,

what is the maximum velocity?

a. 31.4 mm/s

b. 5 mm/s

c. None of the above

d. Both are correct

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 7

Review: Fundamental of Vibration

Which statement below is TRUE?

a. Velocity lags displacement by 90o

b. Acceleration leads displacement by 90o

c. Acceleration lags velocity by 90o

d. None of the above

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 8

Review: Fundamental of Vibration

Which vibration unit below relate to fatigue?

a. Displacement

b. Velocity

c. Acceleration

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 9

Review: Fundamental of Vibration

Which vibration unit to be used if we want to measure vibration of

a high speed machine?

a. Displacement

b. Velocity

c. Acceleration

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 10

Review: Fundamental of Vibration

What is the parameter responsible to absorb the vibration energy?

a. Mass

b. Stiffness

c. Damping

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 11

Review: Fundamental of Vibration

If X is the maximum displacement,

where is the maximum velocity?

a. A

b. B

c. C

c. D

X

A

B

D

time

amplitud

e

C

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 12

Review: Fundamental of Vibration

A

B

C

sensor

Where is the position of maximum acceleration if

the sensor measures maximum displacement?

a. A

b. B

c. C

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Lecture Note, Mechanical Vibrations, Semester II/2012-2013 13

Review: Fundamental of Vibration

If the sensor measures maximum velocity,

where is the position of maximum displacement?

a. A

b. B

c. C

B

C

C

sensor

A