discussion force vibration abos

7/29/2019 Discussion Force Vibration Abos

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MOHD AIDIL MUNIR BIN KHIDER 2009617152

RESULT

Experiment Position Value Damper Distance,b (mm)

1 Open 0

2 Open 150

3 Closed 150

4 Closed 550

Experiment 1: For no damper, b= 0 (Open)

Data Recorded:

Mass beam = 1.68 kg.

Mass unbalance = 0.772 kg.

Beam, L = 700 mm @ 0.7 m.

a = 650 mm @ 0.65 m.

k = 3.0N/mm @ 3000M/m.

SAMPLE CALCULATION:

1) Angular natural frequency,

()() ()


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2) Natural frequency,

()()

()

3) Period,

()()

()()

4) Unbalanced Force,F0

F0 = mass unbalance x a x = 0.772 x 0.65 x 67.962

= 2.318 KN

5) For


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Frequency, fAmplitudes, x,

(mm)

2.0 0.0 12.566 5.41 0.0

3.0 0.0 18.85 3.05 0.0

4.0 0.0 25.133 2.70 0.0

5.0 0.05 31.416 2.16 0.065

6.0 0.05 37.699 1.80 0.065

7.0 0.075 43.982 1.55 0.097

8.0 0.15 50.265 1.35 0.194

8.1 0.2 50.894 1.33 0.259

8.2 0.2 51.522 1.32 0.259

8.3 0.3 52.150 1.30 0.388

8.4 0.4 52.779 1.29 0.517

8.5 0.4 53.407 1.27 0.517

8.6 0.65 54.035 1.26 0.841

8.7 1.05 54.664 1.24 1.358

8.8 1.45 55.292 1.23 1.876

8.9 1.2 55.920 1.22 1.552

9.0 0.8 56.549 1.20 1.035

10.0 0.25 62.832 1.08 0.323

11.0 0.15 69.115 0.98 0.194

12.0 0.1 75.398 0.90 0.129

13.0 0.05 81.681 0.83 0.065

14.0 0.05 87.965 0.77 0.065

Table 4.1.1.1: Data for Experiment 1


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Experiment 2: For damper, b= 150mm (Open)

Data Recorded:



Beam, L = 700 mm @ 0.7 m.

a = 650 mm @ 0.65 m.

Damper constant, d = 5 Ns/m.

k = 3.0N/mm @ 3000M/m.

1) Moment of Inertia, I0

()()

2) Degree of damping, D

()()()()

3) Damped Oscillation,

() ( )


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(mm)

2.0 0.0 12.566 5.41 0.0

3.0 0.0 18.85 3.05 0.0

4.0 0.0 25.133 2.70 0.0

5.0 0.0 31.416 2.16 0.0

6.0 0.0 37.699 1.80 0.0

7.0 0.0 43.982 1.55 0.0

8.0 0.05 50.265 1.35 0.065

8.1 0.05 50.894 1.33 0.065

8.2 0.05 51.522 1.32 0.065

8.3 0.1 52.150 1.30 0.129

8.4 0.1 52.779 1.29 0.129

8.5 0.1 53.407 1.27 0.129

8.6 0.1 54.035 1.26 0.129

8.7 0.1 54.664 1.24 0.129

8.8 0.1 55.292 1.23 0.129

8.9 0.1 55.92 1.22 0.129

9.0 0.15 56.549 1.20 0.194

10.0 0.15 62.832 1.08 0.194

11.0 0.15 69.115 0.98 0.194

12.0 0.15 75.398 0.90 0.194

13.0 0.15 81.681 0.83 0.194

14.0 0.15 87.965 0.77 0.194

Table 4.1.2: Data for experiment 2


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Experiment 3: For damper, b= 150mm (Closed)

Data Recorded:



Beam, L = 700 mm @ 0.7 m.

a = 650 mm @ 0.65 m.


k = 3.0N/mm @ 3000M/m.


()()()()

2) Damped Oscillation, () ( )


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(mm)

2.0 0.0 12.566 5.41 0.0

3.0 0.0 18.85 3.05 0.0

4.0 0.0 25.133 2.70 0.0

5.0 0.0 31.416 2.16 0.0

6.0 0.0 37.699 1.80 0.0

7.0 0.0 43.982 1.55 0.0

8.0 0.0 50.265 1.35 0.0

8.1 0.0 50.894 1.33 0.0

8.2 0.0 51.522 1.32 0.0

8.3 0.0 52.150 1.30 0.0

8.4 0.0 52.779 1.29 0.0

8.5 0.0 53.407 1.27 0.0

8.6 0.0 54.035 1.26 0.0

8.7 0.0 54.664 1.24 0.0

8.8 0.0 55.292 1.23 0.0

8.9 0.0 55.92 1.22 0.0

9.0 0.0 56.549 1.20 0.0

10.0 0.15 62.832 1.08 0.194

11.0 0.15 69.115 0.98 0.194

12.0 0.1 75.398 0.90 0.129

13.0 0.1 81.681 0.83 0.129

14.0 0.1 87.965 0.77 0.129



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Experiment 4: For damper, b= 550mm (Closed)

Data Recorded:



Beam, L = 700 mm @ 0.7 m.

a = 650 mm @ 0.65 m.


k = 3.0N/mm @ 3000M/m.


()()()()

2) Damped Oscillation, () ( )


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(mm)

2.0 0.0 12.566 5.37 0.0

3.0 0.0 18.85 3.46 0.0

4.0 0.0 25.133 2.68 0.0

5.0 0.0 31.416 2.15 0.0

6.0 0.0 37.699 1.79 0.0

7.0 0.0 43.982 1.53 0.0

8.0 0.0 50.265 1.34 0.0

8.1 0.0 50.894 1.33 0.0

8.2 0.0 51.522 1.31 0.0

8.3 0.0 52.150 1.29 0.0

8.4 0.0 52.779 1.28 0.0

8.5 0.0 53.407 1.26 0.0

8.6 0.0 54.035 1.25 0.0

8.7 0.0 54.664 1.23 0.0

8.8 0.0 55.292 1.22 0.0

8.9 0.0 55.92 1.21 0.0

9.0 0.0 56.549 1.19 0.0

10.0 0.0 62.832 1.07 0.0

11.0 0.05 69.115 0.98 0.065

12.0 0.05 75.398 0.89 0.065

13.0 0.05 81.681 0.83 0.065

14.0 0.05 87.965 0.77 0.065



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Figure 4.1: Graph versus


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DISCUSSION:

Based on the graph that has been plotted, it approve that the damper is

reducing the vibration period and amplitude. The distance of the lever arm b is also

effected the vibration as the distance of the damper came closer to beam, the

vibration that cause by the exciter has been hugely reduced. Most of the experiment,

the oscillation will occur when the frequency reached 4 Hz.

The plot of the result almost gets the same wave between them, which is get

high amplitude between 7 until 9 of frequency. The higher amplitude that we get is

from experiment 1 which is without damper. But the result is totally changed when we

do the experiment 2, 3, and 4 with damper. The value of amplitude is hugely

reduced. In case to compare the result between different positions of needle valve,

the amplitude of open needle valve is higher compare with close needle valve like we

did in experiment 2 and 3.In experiment 4 using close needle valve, we get to

minimize the value of amplitude with increasing the value of distance lever arm b.

That is the comparison between experiment 3 and 4.

The result maybe not so accurate because of several reasons.

The marker (ball pen) is not 100% suit with its holder at mechanical

recorder. This apparatus should have its own marker to get theaccurate data.

The control unit is being control manually by human.

The graph paper not smoothly rotates. These mechanical disadvantagehopes can be minimizing in the future for us to get a better result.


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CONCLUSION:

In conclusion, the objective of all this four experiment is achieved. The

resonances can be seen in different damping condition and different length. In order

to reduce the errors, some consideration has to be taken to improve the experiment.

In my opinion, this universal vibration system should its own marker (constant) to

record the data in order to get more accurate result. Therefore, it will reduce all the

errors from occur. Lastly, during taking the data make sure the equipment is been

setting like in lab sheet before start the experiment.

REFERENCE

1) Vector Mechanical for Engineering DYNAMICS), Mc Graw Hill 8th Edition.

2) Vector Dynamics and Vibration, A. R. Zamri, UiTM

3) Acoustics, waves and oscillations, by S. N. Sen (Professor.)

4) Waves And Oscillations, R N Chaudhuri 2001

5) http://personal.cityu.edu.hk/~bsapplec/theoryof.htm

6) http://en.wikipedia.org/wiki/Vibration

7) http://www.roymech.co.uk/Useful_Tables/Vibrations/Free_Vibrations.html

discussion force vibration abos

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