Vibration Analysis

VIBRATION ANALYSIS

 A.K.SINHA  AGM (TURBINE) (TURBINE) PSTS(HQ), NOIDA

VIBRATION VIBRA TION ANAL AN ALYSIS YSIS TECHNIQUES  FREQUENCY SPECTRUM

 ORBIT ANAL AN ALYIS YIS

 MAPPING

OF PEDESTAL PEDESTAL / CASING / FOUNDATION AROUND THE

PROBLEMATIC AREA SHOULD BE CONDUCTED AN ALYSIS YSIS  PHASE ANAL  BODE

/ NYQUIST PLOT

 SHAFT

CENTER LINE ANALYSIS

FULL FREQUENCY SPECTRUM

FULL FREQUENCY SPECTRUM (CASCADE PLOT)

Y

SHAFT ORBIT

X

Proximity Probes

ORBIT ANALYSIS

MAP’PING – Measurement of Amplitude & Phase A

network is drawn on Bearing Pedestal / Secondary

Grout / Foundation Bolt / Anchor Plate / Main Foundation Area in all three principal direction (Horizontal, Vertical and Axial). The

Phase and Amplitude for running frequency

component at each location are measured during steady state operation of the machine, by moving the vibration pick ups at pre-determined locations

MAP’ping of Bearing Pedestal, Secondary Grouting in Vertical direction 3

2 1 9 8

Foundation Bolt

7

Bearing Pedestal

6 5 4

Base Plate

B D

Left

15

C

21

14 13

A

11

12

10 18

20

Right

17 19

16

Secondary Grout

EVENT TIMER

Ø2 Ø1

360 0 T DIFFERENCE BETWEEN TWO EVENTS = (Ø2

 Ø1 /3600) X T

 – 

EVENT TIMER : DIRECTION OF PROPAGATION

CASE - B

CASE - A Ø+

Ø

Ø Ø

Direction of Propagation

Ø+

Ø

Direction of Propagation

PHASE ANALYSIS  CONSTANT AND

 FLUCTUATING

 CYCLIC

STEADY PHASE ANGLE

PHASE ANGLE

PHASE ANGLE

 ROTATING

PHASE ANGLE

USES OF PHASE ANGLE MEASUREMENT  BALANCING

 STRUCTURE

 DETECTION  RUN

MOTION STUDY

OF RESONANCE FREQUENCY

UP & RUN DOWN BEHAVIOUR

 BODE

PLOT

 HEALHINESS

OF MATING SURFACES OF TWO VIBRATING

MASSESS  UNDERSTANDING

THE DEFLECTION MODE OF THE SHAFT

UNDERSTANDING THE DEFLECTION MODE OF THE SHAFT

B1

B2

B3

B4

BODE PLOT

NYQUIST PLOT

SHAFT CENTRE LINE PLOT

VIBRATION ANALYSIS CHART NATURE OF FAULT

FREQUENCY OF DOMINANT VIBRATION

DIRECTION

ROTOR UNBALANCE

1x RPM

RADIAL

MISALIGNMENT & BENT

USUALLY 1x RPM, IN CASE OF SEVERITY:- 2 x

RADIAL /

SHAFT

RPM, & SOMETIMES HIGHER HARMONICS

 AXIAL

BEARINGS LOOSENESS IN

SUB-HARMONICS OF SHAFT RPM, EXACTLY ½

RADIAL

HOUSINGS

OR 1/3 x RPM, SOMETIMES, HIGHER HARMONICS ALSO

OIL WHIRL OR WHIP IN

SLIGHTLY LESS THAN HALF OF SHAFT SPEED

JOURNAL BEARINGS

(42% TO 48%)

MECHANICAL LOOSENESS

2 x RPM, SOME TIMES 1 x RPM ALSO

RADIAL

ANY DIRECTION

FLOW INDUCED

BLADE & VANE PASSING FREQUENCIES AND

RADIAL /

TURBULENCE

HARMONICS

 AXIAL

ELECTRICALLY INDUCED

1 x RPM OR 1 OR 2 TIMES SYNCHRONOUS

RADIAL /

VIBRATIONS

FREQUENCY

 AXIAL

RESONANCE IN

GETS EXCITED WHEN ROTOR SPEED OR ITS

 ANY

STATIONARY

HARMONICS MATCHES WITH NATURAL

DIRECTION

COMPONENTS

FREQUENCY OF THE AFFECTED COMPONENTS

STEPS FOR RESOLVING THE VIBRATION PROBLEM  COLLECTION

 STUDY

OF OPERATING PARAMETERS

OF

HISTORY

OF

VIBRATION

BEHAVIOUR

/

OVERHAULING REPORTS / RECURRING PROBLEM FACED  INTERACTION

 COLLECTION

WITH O&M PERSONNELS

OF DETAILED VIBRATION BEHAVIOUR AT VARIOUS

CONDITIONS OF OPERATION LIKE NO LOAD RUN, RUN UP, RUN DOWN, WITH AND WITHOUT EXCITATION, PART AND FULL LOAD OPERATION ETC.  VIBRATION

ANALYSIS TO NARROW DOWN THE REASONS OF

HIGH VIBRATION

STEPS FOR RESOLVING THE VIBRATION PROBLEM  FORMULATION

OF ACTION PLAN (SHORT TERM / LONG TERM)

 IMPLEMENTATION

 RESPONSE

OF ACTION PLAN

OF MACHINE AFTER IMPLEMENTATION OF ACTION

PLAN  FRESH

VIBRATION ANALYSIS, IF THE PROBLEM PERSISTS

 IMPLEMENTATION



OF NEW ACTION PLAN

THE CYCLE OF VIBRATION ANALYSIS AND IMPLEMENTATION OF ACTION PLAN CONTINUES TILL THE VIBRATION PROBLEM IS SATISFACTORILY RESOLVED

KNOW YOUR MACHINES  KNOWLEDGE

 VIBRATION

OF BEHAVIOUR FOR SIMILAR TYPE OF MACHINES

PRONE AREAS

 INFLUENCE

OF PARTICULAR OPERATING PARAMETER

CONCLUSION  INTELLEGENT

VIBRATION

MEASUREMENT

IS

THE

MOST

IMPORTANT ACTIVITY IN RESOLUTION OF ANY VIBRATION PROBLEM  UNDERSTANDING

OF PRODUCT IS VERY IMPORTANT FOR

 ANALYSIS  PROTOCOLS

/ PARAMETERS / TRENDS / OVERHAUL REPORTS

/ OTHER DOCUMENTS SHOULD BE REFERED / STUDIED FOR BETTER ANALYSIS  EVERY

FEEDBACK AND OBSERVATION ARE IMPORTANT FOR

TROUBLESHOTING

THANK YOU