status of the em vib tests

GLAST LAT Project GSFC, October 2003

LAT-PR-0XXXX 1

Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope

Status of the EM Vib Tests

GLAST Large Area GLAST Large Area Telescope:Telescope:Tracker Subsystem

INFN - Bari


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OutlineOutlineTest strategiesFirst resultsPanel vib plan: tests done!Tray thermal plan: tests to be doneTower vib plan: ok plan and procedure ready

for TRR,fixture calibration done, tower test to be doneTower thermal-vacuum plan: TBREM Matrix planReference LAT Documents:

1. LAT-MD-00408, LAT Instrument Performance Verification Plan2. LAT-SS-00788, LAT Environmental Specification3. LAT-TD-01005, Thermal Test Results on Thick Converter Mock-up

Trays4. LAT-TD-01249, Thermal Test Results for Pre-Engineering Model

Trays5. LAT-PS-01584, LAT Tracker Tray SSD Ladder Panel Assembly

Procedure6. LAT-TD-01004, EM Tray Vibration Test Plan 7. LAT-TD-01037, EM Tray Thermal Test Plan


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EM Tray vib levelsEM Tray vib levels

Frequency (Hz)

ASD QualLevel

(g2/Hz)

ASD AcceptLevel

(g2/Hz)

ASD LaunchLevel(g2/Hz)

20 0.026 0.013 0.006520-50 +6 dB/oct +6 dB/oct +6 dB/oct

50-800 0.16 0.08 0.04800-2000 -6 dB/oct -6 dB/oct -6 dB/oct

2000 0.026 0.013 0.0065Overall 14.0 grms 10.0 grms 7 grms

Duration 2 min 1 min 1 min

Random vibration

Frequency

(Hz)

ASD WN Level(g2/

Hz)

Overall

grms

Duration

(min)

20 ÷ 2000 10-4 0.45 1

White NoiseFrequency

range20 2000 Hz

Sweep rate 2 oct/min

Target Amplitude

0.5 / 0.25 g0-pk

Sine sweep


LAT-PR-0XXXX 4

Tray vib set upTray vib set upAccelerometers position:•Control: two mono-axial accelerometers positioned on two of the four L-shaped block TP1&TP2

•Fixture: three mono axial accelerometers placed on a corner on one of the four L-shaped block TP6

•Tray: one three-axial accelerometer in the middle TP5

Centrotecnica set up:- 1 LDS V864LT shake table- 2 fixtures - 9 read out channels- 4 trays/day test rate capability

W side on the top


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EM Tray vib sequence EM Tray vib sequence thrust axisthrust axis

Step Description Test Level1 Fixture, tray and

accelerometers mounting

2 Fixture calibration and tray resonance

searchSine sweep 0.25 g 0-pk

3 Pre-random vibration White noise 0.45 grms

4 Random vibration Random vibration Launch

5 Post/Pre-random vibration White noise 0.45 grms

6 Random vibration Random vibration Acceptance

7 Post/Pre-random vibration White noise 0.45 grms

8 Random vibration Random vibration Qualification

9 Post-random vibration White noise 0.45 grms

10 Normal mode check Sine sweep 0.25 g 0-pk

11 Dismounting12 Test completion


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EM Trays: some results (1) EM Trays: some results (1) Sine sweep before/after random Random vibration + White noise

Resonance search:0= 815 Hz, Q 51

Resonance check:0= 809 Hz, Q 49

Z accelerometer response

X accelerometer response

Y accelerometer response


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Light≈ 1000Hz

≈ 800Hz Heavy tray

Mid tray

EM Trays: some results (2)EM Trays: some results (2)

≈ 660Hz


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EM Trays: some results (3)EM Trays: some results (3)

“Watch-dog”Input-notched: 13.6 grms

Output-notched: 59.6 grms

Applied notching on qual ASD: output ≤ 16 g2/Hz ( Q=10) “Watch-dog”

Heavy tray (TS05) Q=100 @ 660Hz Output-expected: 140.4 grms


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All trays first mode › 500 Hz

530

EM Trays: summaryEM Trays: summaryVib test pass criteria: / < 5%

/ < 2%


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EM Tower vib levelsEM Tower vib levelsSinusoidal vibration

Modal survey Random vibration: new level

TKR Acceptance (g)

Qualification (g)

Lateral (X) 3.7 4.6Lateral (Y) 3.7 4.6Axial (Z) 6.8 8.5

Sine burst: quasi static test@25Hz

Frequency range 20 2000 HzSweep rate 2 oct/minInput Amplitude 0.15 g0-pk

Alarm Levels ± 1 dBUpper Abort Level 0.25 g0-pk

Lower Abort Level - 2 dB


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Tower vib set up: Tower vib set up: Acceleromete

r. #Side-wall Tray # Location

Read-out axis

1 +X 19 (top) +x, -y corner x2 +X 19 (top) +x, +y corner z3 +X 19 (top) +x, +y corner x4 +X 10 Center of structural close-out x

5 +X 1 (bottom) +x, +y corner z

6 +X 1 (bottom) +x, +y corner x

7 +Y 19 (top) +y, -x corner y8 +Y 10 Center of thermal boss y

9 +Y 1 (bottom) +y, -x corner z

10 +Y 1 (bottom) +y, -x corner y

11 -X 10 Center structural close-out x12 -Y 10 Center of thermal boss plane y13 - 19 (top) Center of the top side of the top tray z

14 - 1 (bottom)

Bottom side of the bottom tray near the +x, -y corner x

15 - 1 (bottom)

Bottom side of the bottom tray near the +x, +y corner y

16 - 1 (bottom) Center of the bottom side of the bottom tray z

Accelerometer locations


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Accelerometers locationAccelerometers location

1

72

3

4

5

6

8

9

10

1112

13

1416

15

11

7722

33

44

55

66

88

99

1010

11111212

1313

14141616

1515


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Fixture calibrationFixture calibration


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EM Tower vib sequence X,Y,Z axisEM Tower vib sequence X,Y,Z axisFor each axis

Run # Test Description Frequency Comments

1 Modal survey Input: 0.15 g (20 – 2000 Hz)

2 Sinusoidal vibration 5 – 50 Hz Qual level


4 Random Vibration (-6 dB) Input 20 – 2000 Hz 1 min duration


6 Random Vibration (- 3 dB) Input: 20 – 2000 Hz 1 min duration

7 Modal survey Input: 0.15 g 20 – 2000 Hz

8 Random Vibration (Full level) Input: 20 – 2000 Hz 1 min duration


10 Random Vibration (Full level) Input: 20 – 2000 Hz 2 min duration


12 Sine burst (1/4 level) 25 Hz 5 cycles13 Sine burst (1/2 level) 25 Hz 5 cycles14 Sine burst (full level) 25 Hz 5 cycles

15 Modal Survey Input: 0.15 g (20 – 2000 Hz)


LAT-PR-0XXXX 15

EM matrixEM matrix

Item

Quantity

Quantity to test

Sine burst (static equivalent acceleration)

Random Vibe + m

odal survey

Sinusoidal vibration

Functional

Thermal Cycle

Thermal balance

Thermal Vacuum

Test site

Panels 24 24 QualZ axis

Centrotecnica (vib)

Live Trays

5 1 QualZ axis

Qual Centrotecnica (vib)Alenia (thermal-vac)

Dummy Trays

19 5 vib19 ther

Qual Z axis

Qual Centrotecnica (vib)INFN Perugia (in Terni) (thermal)

Tower 1 1 Qual X,Y,Z

QualX,Y,Z

QualX,Y,Z

Qual Italy


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Test plans & procedures: EM open Test plans & procedures: EM open itemsitems

Tower vib test• FEM from Hytec • Warning and abort levels• Discussion of non-conformances and procedure variations• Add a Sinusoidal test levels at protoflight level? Add a step

…


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Flight unitsFlight units

• New random level: Qual tower Protoflight tower• Trays tower A vib level?• Trays flight vib level?


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Towers: random levelsTowers: random levels

Tower A

Old levels (general GEVS levels)

New levels

Qualification(12.3 grms, 2 min)

Workmanship(6.8 grms, 1

min)

Trays for tower A Qualification(14 grms, 2 min)

Qualification ??(14 grms, 2 min)

Towers 1-16 Acceptance(8.7 grms, 1 min)

Workmanship(6.8 grms, 1

min)

Trays for towers 1-16

Acceptance(10 grms, 1 min)

Acceptance ??(10 grms, 2 min)


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Tray assembly&test sequenceTray assembly&test sequence

Tray factory (panels)

Vibration test

Ladder factory

Tray assembly: ladders and MCMs on trays

Thermal cycles

Stacked cosmic rays*

Electrical test

Fast electrical test*

Tower assembly* Live trays

Vacuum bakeout

Plyform

Centrotecnica

Roma

G&A

G&A Mipot