Vibration and mechanical stability status and perspectives · 2015-01-27 · Vibration and...

Slide: 1

ISDD Friday Lecture, 9 April 2010

Vibration and mechanical stabilitystatus and perspectives

L. Zhang, M. Lesourd

Vibration: A rapid oscillation of a particle, particles, or elastic solid or surface, back and forth across a central position

The American Heritage® Science Dictionary

Slide: 2ISDD Friday lecture: Vibration & mechanical stability / L. Zhang, 9-April-2010

FundamentalsHow to measure nm level of vibrationGround vibrationVibration of mechanical structureVibration propagationBeam stabilityVibration investigation

Vibration on the EXPH floorCooling flow induced vibrations

Summary and perspectives

Outlines


30.5 31 31.5 32 32.5-150

-100

-50

0

50

100

150

time (s)

velo

city

(µm

/s)

Temporal velocity

VRMS=30.382 µm/s

0 20 40 60-150

-100

-50

0

50

100

150

time (s)

velo

city

(µm

/s)

Temporal velocity (Response to mass drop)

Fundamentals

Temporal domain Frequency domainFourier transform

twin

Some termsWindow length twinSampling rate (number of samples per second): fs=1/ΔtBandwidth: f<fmax=fs/CNyquist(CNyquist ≥ 2)Spectral resolution Δf=1/twin

FFT

0 20 40 60 80 10010-2

10-1

100

101

102

Frequency (Hz)

V sp (µ

m/s

)

Spectral velocity

IFFT(+phase)


Fundamentals

In frequency domain

3 frequency rangesLow ( f < 1 Hz)

Ocean wavesmicro seismic activities

Intermediate (1<f<100 Hz)Mechanical resonant frequenciesTraffic, machineoperations, water flow, wind,…

High ( f >100 Hz)Generated by small electro-mechanical structuresVibro-acousticMuch smaller level

10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

dis

plac

emen

t (µm

)

3D spectral displacement at the ESRF site

VerticalNorth-SouthEast-West

Low frequency

Intermediate frequency

High frequency


Fundamentals

10-1 100 101 102101

102

103

Frequency (Hz)

Tran

sfer

func

tion

V/(m

/s)

Geophone L4C transfer function

gama0=0.283

gama=0.5gamacr=0.71

Sensors (transducers)Geophones (L4C: 285 V/(m/s), sensor noise < 80 pm (RMS) < dRMS-ESRF-Site/1000)Seismometers (Guralp CMG-3ESP: 0.03 ~ 50 Hz)Accelerometers (strong, high-f Vib.)Laser vibrometer (d & V, d (>2nm))Displacement sensors (capacitive,…)


FundamentalsData acquisition systems (DAS)

OROS, RefTekStandalone or networkDynamical range (12 16 24 bits, 60 80 120 dB)Lowest input range: 17mV, 200mV (RT)Internal noise ~ 10-7:16 nV (RT) @ 200mV

10 pm (with geophone L4C)

Data processing systemsMatlab, SAC, Star,...OROS

GPS receiver

TCP/IP

TCP/IP

Server

Client

Vibration signal

DAS

Data baseArchiveData processing Data storage

GPS receiver

TCP/IP

TCP/IP

Server

Client

Vibration signal

DAS

Data baseArchiveData processing Data storage


Fundamentals

Measurement quantities

10-1 100 10110-2

10-1

100

101

102

103

Frequency (Hz)

spec

tral

acc

eler

atio

n (µ

m/s2 )

3D spectral acceleration at the ESRF site


10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

dis

plac

emen

t (µm

)



10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

vel

ocity

(µm

/s)

3D spectral velocity at the ESRF site


Displacement VelocityVelocity Acceleration

Spectra of Velocity Flatter than those of displacement, accelerationLess dynamic range requirement from DASOne operation (integration or differentiation) to obtain displacement or acceleration

Most convenient to measure velocity geophone widely used

integration differentiation

*(2πf ) /(2πf )


Fundamentals

Measurement quantities

10-1 100 10110-2

10-1

100

101

102

103

Frequency (Hz)

spec

tral

acc

eler

atio

n (µ

m/s2 )

3D spectral acceleration at the ESRF site


10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

dis

plac

emen

t (µm

)



10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

vel

ocity

(µm

/s)

3D spectral velocity at the ESRF site


Displacement Velocity Acceleration

Sensors vs frequency rangeVery low frequency range displacement sensors (positioning and alignment,…)Intermediate frequency range velocity sensors: geophone (seismology, geophysics, petroleum exploration,…)High frequency range accelerometers(industries: auto, aeronautics,..)

integration differentiation

*(2πf ) /(2πf )


0 20 40 60 80 10010-2

10-1

100

101

102

Frequency (Hz)

V sp (µ

m/s

)

Spectral velocity

Temporal domainVelocity of unit mass: v(t)

Kinetic energy:

RMS of v(t):

FundamentalsPower Spectrum Density (PSD)

0 20 40 60 80 10010-4

10-2

100

102

Frequency (Hz)

PSD

((µm

/s)2 /H

z)

Power Spectrum Density

VRMS=30.385 µm/s

2)(21)( tvte =

∑=n

RMS tvn

V 2)(1

Frequency domainVelocity spectrum: V(f)Power spectrum density:(kinetic energy per unit of frequency interval)

ffVPSD

Δ=

2)(21

∫ ∗= dfPSDVRMS

∫ ∗= dfPSDPtotal

30.5 31 31.5 32 32.5-150

-100

-50

0

50

100

150

time (s)

velo

city

(µm

/s)

Temporal velocity

VRMS=30.382 µm/s


FundamentalsPower Spectrum Density (PSD)

Independent of window length

Spectral displacement (velocity, acceleration): window length twindependantPSD : independent of window length twinPSD is appropriate for vibration spectra comparison

PSD

Spectral displacement


How to measure nm vibrationCapacitive sensor test setup

A moving surface driven by a piezo-actuator generates a controlled displacement d(t) = A*sin(2ft)Capacitive sensor and Laser vibrometer measure simultaneously this controlled displacementTested sensors:― LION C7-C (resolution: pp=1.5nm,

rms=0.1nm, range 10um)― PI Seca (range 20 um)

Test setup with capacitive sensor

Laser vibrometer

Capacitivesensor

PiezoActuator

A*sin(2ft)


57 58 59 60 61 62 6310-9

10-8

10-7

10-6

10-5

X: 60.01Y: 2.619e-006

Frequency in Hz

PSD

in μ

m2 /H

z VibrometerCapacitive

How to measure nm vibrationCapacitive sensor test results

Piezo-actuator generated d(nm) ~ 1*sin(2ft), f=60 Hz Resonance of the test assembly at 557 Hz excellent agreement between Laser vibrometerand capacitive sensorAt f=60Hz, all sensors measure PSD=2.6x10-6

μm2/Hz, Δf ~ 0.1HzdRMS ~ 0.5 nm dpeak ~ 0.7 nm

Consistent with Piezo-actuator delivered displacement

0 200 400 600 800

10-8

10-6

10-4

Piezo/Capacitive/Vibro tests - 60Hz-1mV-sine

Frequency in Hz

PSD

in μ

m2 /H

z

VibrometerCapacitive

557 Hz


How to measure nm vibrationCapacitive sensor test results

In vibration measurementsCapacitive sensors (PI, Lion) can measure sub-nm (~100pm)Laser vibrometer can measure 1 nm when f>10Hz

In static measurementsCapacitive sensors (PI, Lion) can measure nm-range displacementLaser vibrometer can measure 10 nm

Laser vibrometer measurements sensitive to air refractive index variation (temperature, convection). This limits the measurement accuracy of the laser vibrometer.


Ground vibration Spectra in different sites(Accelerator centres et al. )

Ground vibration decreases with increase in frequency :

Displacement PSD ~ f-4

Spectral displacement ~ f-2

1E-12

1E-09

1E-06

0.001

1

1000

0.01 0.1 1 10 100f (Hz)

PSD

(µm

2 /Hz)

1.FNAL C0 2.FNAL B0 3.Elburn4.FNAL Numi 5.APS Sd E 6.ESRF S137.DESY HERA

1E-111E-091E-071E-050.001

0.110

1000

0.01 0.1 1 10 100f (Hz)

PSD

(µm

2 /Hz)

8.SLAC S109.CERN P410.Asse11.Moxa12.Ellerhoop

W. Bialowons & H. Ehrlichmann, DESY, 2003

PSD ~ f -4


Ground vibrationSpectra at ESRF site

Comparable spectrum in 3DA peak at 3Hz (site resonance)Vibration varies with time― Period of 24H, week

Typical values (in 1-100 Hz)― Day: dpp=1 μm, dRMS= 0.3 μm― Night: dpp=0.15 μm, dRMS= 0.05 μm

10-1 100 101

10-4

10-3

10-2

10-1

100

101

Frequency (Hz)

spec

tral

dis

plac

emen

t (µm

)



Varies with time


LURE

SOLEIL

ESRF

peak-to-peak displacement (µm)

02468

101214

08/10/96 12:00 09/10/96 12:00 10/10/96 12:00 11/10/96 12:00time (dd/mm/yy hh:mm)

Ver

tical

at the ESRFat Orme des Merisiersat the SuperACO

0.14 Hz

0.07, 0.14 Hz

low frequency motion (0.03-1Hz)

Ground vibration


d2sites in Paris=5 km

dParis-Grenoble=500 km

Ground vibration


Ground vibrationSeismic waves

P-wavePrimary (pressure)

S-wavesecondary (shear)

Rayleigh wave

Love wave

Body waves

Surface waves


Ground vibrationSeismic wavesCross-hole test to determine Soil properties

Wave emission by hammer shockMeasurement of wave propagation by geophonesDetermine P- and S- wave propagation speeds Vp & Vs from measurement resultsDetermine soil parameters― Poisson’s ratio

― Young’s modulus

E: a key parameters for EX2 golden slab design

)(22

22

22

sp

sp

VVVV

−

−=ν

2)1(2 sVE νρ +=

Emission Reception


Ground vibrationEarthquake measured at ESRF in 1994

Time : 14-Dec-1994, 9:56:17 - 9:57:30epicenter : Cruseilles near Annecy,

about 100 km from GrenobleMagnitude : 4.5/Richter

P-wave S-wave

time delay of S-wave Δt=15s→ distance from source ~ 90 km

dpp (μm)106

65

84

70

70


Ground vibrationEarthquakes

Date: 26/12/2005Time: 07:58:50 (local time)

01:11:50 (at ESRF)Magnitude: 8.9Epicentre: west coast of Northern SumatraDistance: ~ 11000 km (surf)~ 9100 km, v ~11.7 km/s

Date: 03/12/2000Time: 05:24:00 (local time)Magnitude: 2.3Epicentre: Domène, Francedistance: 15 ~ 20 km

Distance effects !!


Ground vibrationTraffic generated vibration

Main contribution in the vibration noise (period of 24H, week)

Road traffic with an 26-T truck, Feb 1993

0

1

2

3

4

5

0 20 40 60 80 100

distance from road - lane (m)

d pp

(μm

) Av. Martyrs S-->G

Av. Martyrs G-->S

motorway A480

Distance effects― at least 30 m necessary to have

limited effects on the ESRF site


Ground vibrationTramway Line-C extension(Vibrations influences)

1st vibration studies made by ESRF― In 1993, UJF campus, SMH― In 1999, Fontaine

Vibration concerns expressed by ESRF and CNRS to Authorities (Prefecture, Mairie, DDE)Coordinated studies and meetings―Territoire 38―Acouplus―VibraTec― ESRF, CNRS, CEA

Study made by VibraTec in 2008


Ground vibrationTramway Line-C extensionVibration study

Vibration sources (generated by tramway, measured at 3 m from rail)Vibration propagation and attenuation in the soilVibration transmission to the ESRF buildings (EXPH)


Ground vibrationTramway Line-C extensionResults of vibration study

Source : tramway Citadis on recent railAttenuation rate: ~ 0.25 dB/mDistance between future Line-C rail to ESRF central building: 180 mEstimated vibrations level due to future tramway < actual ground vibration level at the ESRF siteEfforts requested so that the Tramway line-C should not generate higher vibrations than existing ones !


Simple model MKCMass: mStiffness of the spring: kDamping constant: c (=2γm)Resonant frequency:

Transfer function

Vibration of mechanical structure

Mass Spring Damper system(1 DOF system)

mkf

ππω

21

20

0 ==

xg

020

2 **21

ωωγωω jXXFrF

g +−==

10-1 100 10110-2

10-1

100

101

102

Normalised frquency f/f0

Am

plitu

de

response function of a MKC model

gama=0.03gama=0.1gama=0.2

10-1 100 101

-150

-100

-50

0

Normalised frquency f/f0

phas

e (d

egre

e)response function of a MKC model

gama=0.03gama=0.1gama=0.2


ESRF magnet-girder assembly MGAs

1st mode : lateral rocking due to the deformation of 3 jacks. A global mode


Complex system(Multi DOF system)


Passive damping systemsWidely used, effective, cheapDamping Plate, Damping PadDamping LinkTuned Vibration Absorbers (TVA)

Active damping systemsSome commercial products - active vibration ISOLATION system:― TMC stacis (PEL)― Halcyonics (OML, ID10, SSL)― HWL Sc. Instr.

Acoustic noise reduction deviceCould be expensiveDesign specificActuator - sensor limitation


Vibration Damping


High performance in vibrationInsufficient stiffness for static positioning


Damping Plates for MGA

2mm thicksteel plate

0.5mm thinsteel plate0.18mm VEM

cross section (not in scale)


Increase stiffness and f0Damping factor > 8


Damping links for MGA

GMF :Girder Mounting Fixture

FMF :Floor Mounting Fixture

VEM :ViscoElasticMaterial


Implemented in 2000Significant e-beam stability improvement


Damping links for MGA(Performance on e-beam)

PSDpk rms4-12Hz

μm2/Hz ratio μm rationoDL 158 11.7

DL 3.2 49 3.1 3.8


1st Tested in 2003, in collaboration with CERN1st Installation at ESRF - PEL in 2007Tested and commissioned in 2008-20 dB (2~40 Hz), -10 dB (1~100 Hz)70 k€ for 3 mounts


Active vibration isolation systems - (TMC Stacis 2100)

10-1 100 101 102-50

-40

-30

-20

-10

0

10

20 PEL STACIS ON - AC OFF - Loaded

Frequency in Hz

FrF

(dB

)

ZXY


Used in Optical Metrology LabID10, SSLTest results― Effective damping above 2 Hz― Amplification below 2Hz

~ 7 k€Equivalent: HWL Sc. Instr.


Active vibration isolation systems (Halcyonics)

Floor: 0.2 µmTable: 0.4 µmAFM: 0.7 µm


Vibration propagationMechanical (air) acoustic ground(Helicopter flying over Soleil site, 1996)

Doppler Effects :

s

helico

helico

sV

VV

Vff

−=

Δ 1

Vs : sound speed

Δf/f ~ 1/8 Vhelico ~ 42 m/s

~ 151 km/h

Spectrogram of vertical acceleration (dB.µm/s2)

X 10

X 3


e-beam stability

Jul00 Oct00 Jan01 Apr01 Jul01 Oct010

2

4

6

8

10

12

14

dRMS-horizontal (μm) (4-12 Hz)

The RMS amplitude was reduced10 μm to 2.7 μm (4-12 Hz)12 μm to 4 μm (4-200 Hz)

damping links installation

1000≈= −

quadrupole

beamePSD

PSDratio

30≈−

quadrupole

beameRMS

RMS This ratio agrees with theoretical estimation


e-beam stability

In the frequency range of 4-200 HzdRMS-horizontal = 1 μm, (0.25% of horizontal beam size) @ high-β sectiondRMS-vertical = 0.6 μm, (7.5% of vertical beam size) @ low-β section

at the middle of a high-β straight section (βx = 35.4 m)RMS horizontal = 402 μ m

Δ RMS horizontal ( μ m) 4-12 Hz 4-200 Hzno damping links (μm) 10 12with damping links (μm) 2.7 4damping links + feedback (μm) 0.28 1

at the middle of a low-β straight section (βz = 2,5 m)RMS vertical = 8 μ m

Δ RMS vertical ( μ m) 4-12 Hz 4-200 Hzwith damping links (μm) (μm) 0.5 1damping links+feedback (μm) 0.17 0.6


X-ray beam stabilityExample of ID06 Cinel mono

0 20 40 60 80 100104

106

108

1010 ID06 Cinel Mono - Effect of pumps - X-ray PSD

Frequency in Hz

PSD

in a

.u.

All ONP1 OFFP1 and P2 OFF

0 20 40 60 80 1000

0.5

1 ID06 Cinel Mono - Coherence X-ray ~ vibrations

Frequency in Hz

Coh

eren

ce

0 20 40 60 80 100

10-5

100

ID06 Cinel Mono - Correlation X-ray and vibrations

Frequency in Hz

Dis

plac

emen

t (um

), X-

ray

inte

nsity

in a

.u.

VerticalHorizontal YXray intensity

Correlation between X-ray intensity fluctuation and mechanical vibration

F=24.8, 66.2, 70.3, 78.7, 82.8 Hz1st peak due to vacuum pump 1, other 4 peaks due to pump 2

Remaining peaks probably due to mechanics room for improvement


X-ray beam stability

Example of ID20

Many pumps

0 20 40 60 80 10010-10

10-5

100

ID20 - Effect of pumps - X-ray PSD

Frequency in Hz

Dis

plac

emen

t (um

), In

tens

ity in

a.u

.

Mirror2MonoMirror1X-ray

0 20 40 60 80 100106

108

1010

1012 ID20 - Effect of pumps - X-ray PSD - S1=0.02x3

Frequency in Hz

PSD

in a

.u.

P2 OFFP2 ON


Vibration investigationsVibration on the EXPH floor

Various measurements show vibration increases on the EXPH floor

A vibration survey campaign on all the EXPH floor carried out during summer 2009

4 geophones (vertical, L4C) placed along each beamline (ID or BM)Measurements period: June-30 to July-21, working time

8:00

10:00

12:00

14:00

16:00

18:00

0 5 10 15 20 25 30 35ID/BM #

time m

eas (

hh:m

m)


Vibration investigationsResults of the vibration on the EXPH floor, in 2009


Vibration investigationsPictures of the vibration on the EXPH floor, in 2009

DPP

X

Y

0.356

0.453

0.551

0.648

0.746

0.843

Integrated Amp 1st peak

X

Y42.100

51.871

61.643

71.414

81.186

90.957

Integrated Amp 2nd peak

X

Y

0.862

2.101

3.341

4.581

5.821

7.061

Integrated Amp 3rd peak

X

Y

0.298

1.840

3.383

4.925

6.467

8.009

dpp (μm)(1-100 Hz)

dRMS-Δf=2Hz (nm)(1-20 Hz)




Vibration investigationsPicture of the vibration on the EXPH floor, in 2009

Beamline number - IDxx/BMxx

Freq

uenc

y in

Hz

EXPH floor vibration - acceleration spectrogram (2009)

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 320

10

20

30

40

50

60

70

80

90

100


Vibration investigationsVibration on the EXPH floor

Vibration increased during last 10 years:

Wide bandHigh frequenciesMany peaks

Internal vibration noisesProposal to remedy the situation:

Sources identificationProposition and correctionCollaboration of all staff to limit vibration generation

Set up a procedure to check some new installations in terms of vibration ?

0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

Frequency (Hz)

PSD

(µm

2 /Hz)

EXPH ID26 - Vertical PSD, 2009

Floor 1Floor 2Floor 3Floor 4

0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

Frequency (Hz)

PSD

(µm

2 /Hz)

EXPH ID26 - Vertical PSD, 2009

in 1998


0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

Frequency (Hz)

PSD

(µm

2 /Hz)

EXPH BM20 - Vertical PSD, 2009


0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

Frequency (Hz)

PSD

(µm

2 /Hz)

EXPH BM20 - Vertical PSD, 2009

Floor 1Floor 2Floor 3Floor 4in 1999


Vibration investigationsCooling flow induced vibrations

Commonly used cooling fluids at ESRF:WaterLiquid nitrogenGas (Helium, nitrogen, air)

Vibration due to cooling flowIncrease with flow rateFlexible tube, corrugated tube

Cooling flow optimizationDecrease vibrationsSave pumping capacity (no need to add additional capacity in EX2)Define and regulate necessary flow rate for each componentsCombine serial and parallel connections

Velocity or Re(flow rate)

cooling coef. hcv

LaminarTransition

Turbulent

pressure drop ΔP


Vibration investigationsCooling flow induced vibrations

ExamplesMachine magnet-girder MGAID24 mirrors

0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

G30 CELL 14 - PSD in horizontal Y direction, no Flow

Frequency in Hz

PSD

in μ

m2 /H

z

FloorGirderQuad centreQuad downstream

0 20 40 60 80 10010-10

10-8

10-6

10-4

10-2

G30 CELL 14 - PSD in horizontal Y direction, with Flow

Frequency in Hz

PSD

in μ

m2 /H

z

FloorGirderQuad centreQuad downstream

10 20 30 40 50 60 70 80 90 10010

-10

10-8

10-6

10-4

10-2

frequency (Hz)

PSD

(µ2 /H

z)

Average transverse PSD of floor, Mirrors in ID24

ID24-FlhyID24-M1hyID24-M2hy


Vibration investigationsCooling flow induced vibrations1st measurement results (ID24 mirror)

Natural frequencies: 376, 710 HzWater flow in corrugated tube excites the resonant frequencies of the piping systemFlow rate, dtube, f dper =5~ 10 mm

0 20 40 60 80 100Time in sec - (flow rate varied)

0

100

200

300

400

500

600

700

Acceleration in μm/sec2

Freq

uenc

y in

Hz

(0 l/min) (5 l/min) 0.5 l/min4 l/min

dper

710 Hz

376 Hz


Vibration investigationsCooling flow induced vibrations1st measurement results (ID24 mirror)

The 2 peaks at f=376, 710 HzVery high accelerationBut also spectral displacement comparable to the peak at 3 Hz

L/min


Summary and perspectivesSome points on vibration at ESRF

Ground vibration levelSlight degradation of stability on the EXPH floorX-ray beam vibration stability (>1Hz) can be seriously impacted by internal vibration sources

Proposals:Investigation to identify vibration sources in EXPH1Investigation on cooling flow induced vibrationProposition for improvementsCall for collaboration of all staff to limit vibrationsImprove awareness of vibration aspects

QuestionsShall we set up a procedure to check new installations in terms of vibration ?Can we reinforce dynamic analysis capability to assist and improve design of new systems?

Improve stability ☺ ☺

Resources


Acknowledgement

Many thanks to

Trainee students: Alice Lan, Renaud FineFIV-WG: Y. Dabin, T. Mairs, L. Petit

And many colleagues inISDD (ME, Optics,…)EXPD (ID06, ID20, ID24,…)ASD (FE group, L. Farvacque, E. Plouvier,…)BIG


Thank you for your attention !

ISDD Friday Lecture, 9 April 2010

Vibration and mechanical stability status and perspectives · 2015-01-27 · Vibration and...

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Transcript of Vibration and mechanical stability status and perspectives · 2015-01-27 · Vibration and...