(08 11 03)basic vibration

7/21/2019 (08 11 03)Basic Vibration

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PT. Indocement Tarjun Plant November 2008 Prepared by KPS

PS


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1. General Informatio

Vibration


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Vibration(Oscillation)

Vibration!!! (From Dictionary)

The oscillations may be periodicsuch

as the motion of a pendulum or random

such as the movement of a tire on agravel road.
http://en.wikipedia.org/wiki/Periodic_functionhttp://en.wikipedia.org/wiki/Randomhttp://en.wikipedia.org/wiki/Randomhttp://en.wikipedia.org/wiki/Periodic_function


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Where we can

find vibration

?

Clock HP nyt!"n# el$e%

Guitar

iano

arth

"ua#e


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2. Wanna see

vibration ?


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America Washington state

Year : 1940

Name : Takoma bridge

Wind : 17 ~ 18 m/s


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3. Why we

shold

!hec"

Vibration ?

#or what ?


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What "inds of troble

occr in or $lant?


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1. ressre vessel %&an"'

$ea#

rosion

%%%


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2. Valve

$ea#

rosion

&tem bro#en

assing

%%%


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3. (otatin) *+i$ment

% m$, #an-'

$ea#

rosion

&haft bro#en

Vibration

'oupling


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(otatin) *+i$ment &roble


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(otatin) *+i$ment &roble


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If yo "now vibration ?

Cond"t"on mon"tor"n# &ac!"ne d"a#no$"$


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Why vibration?

Belt

vibrationsUnbalance

Mis-alignment

Lub. OilBlade

defects

Stator

defect

Component

resonance

Rotor-

defectGear defect

Bearing

defect

&ound

Oil nalysis

Vibration

Temp


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. /et0s "now

Vibration

1asic


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nde*.

+. Vibration definition

,. Vibration arameters

- mplitude

- Fre"uency

- hase


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1. Vibration definition

The system response(ovement)

correspond to nternal or

e*ternal force.

/ut if there0s no movement1

t0s not vibration


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1. Vibration definition

Vibration means

the state of ob2ect an

that moves repetitively

bac#3for4ard1

right3 left

or up3do4n


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The s4ing of the pendulum


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The s4ing of the pendulum


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The s4ing


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The movement of spring


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1. m$litde1. is$lacement

2. Velocity

3. cceleration


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+. Displacement

icrons ( )

ils+ 5 +3+666mm 5 6.66+mm

+ mil 5 +3+666inch

Dis!acement means the am!it"de

#distance$

bet%een the eaks o& 'ibration


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+. Displacement


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,. Velocity

Distance 5 Velocity 7 Time

mm3sec or in3sec

Distance

Velocity 5 ''''''''''

Time

(e!ocit) means the changing rate

o& Dis!acement #D$ %ith time


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,. Velocity


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8. cceleration

mm3sec, or in3sec,

9g: 5 ; cm3sec,

5 8


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8. cceleration


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X(t)= Xpeaksin wt

v= wXpeakcos wt

a(t)= -w2Xpeaksin wt


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ea#-to-ea# * + , -eak

ea# * 1.414 ,

A& * 0.707 , eak

verage * 0.9

* 0.237 , -eak


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Vibration Bnit

Displacement

or mil ea# to ea#

Velocitymm3s or nch3sec ea#mm3s or nch3sec rms

cceleartionmm3sec, or in3sec, ea#9g: s pea#


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Fre"uency (C)

re5"enc) means the times o&

reetiti'e motion that a 'ibrating ob6ect

generates in 1 second.

The time &or one c)c!e is

a eriod eressed as T

re5"enc) #$ is eressed as 1/T.


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+

f 5 ---- T

+5 ----

eriod('ycle)

Fre"uency (C)


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Fre"uency (C)

Ehen T 5 6.>sec1Fre"uency is obtained as

F5 +36.>5 ,C


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hase

hase is a fre"uency domain

or Fourier transformdomain concept
http://en.wikipedia.org/wiki/Frequency_domainhttp://en.wikipedia.org/wiki/Fourier_transformhttp://en.wikipedia.org/wiki/Fourier_transformhttp://en.wikipedia.org/wiki/Frequency_domain


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(08 11 03)basic vibration

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