glast lat projectgsfc, october 2003 lat-pr-0xxxx 1 gamma-ray large area space telescope status of...
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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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 2
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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 3
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 0.0065
20-50 +6 dB/oct +6 dB/oct +6 dB/oct
50-800 0.16 0.08 0.04
800-2000 -6 dB/oct -6 dB/oct -6 dB/oct
2000 0.026 0.013 0.0065
Overall 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
GLAST LAT Project GSFC, October 2003
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
GLAST LAT Project GSFC, October 2003
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EM Tray vib sequence EM Tray vib sequence thrust axisthrust axis
Step Description Test Level
1 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 Dismounting
12 Test completion
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 6
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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 7
Light
≈ 1000Hz
≈ 800Hz Heavy tray
Mid tray
EM Trays: some results (2)EM Trays: some results (2)
≈ 660Hz
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 8
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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 9
All trays first mode › 500 Hz
530
EM Trays: summaryEM Trays: summaryVib test pass criteria: / < 5%
/ < 2%
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 10
EM Tower vib levelsEM Tower vib levelsSinusoidal vibration
Modal survey Random vibration: new level
TKR Acceptance (g)
Qualification (g)
Lateral (X) 3.7 4.6
Lateral (Y) 3.7 4.6
Axial (Z) 6.8 8.5
Sine burst: quasi static test@25Hz
Frequency range 20 2000 Hz
Sweep rate 2 oct/min
Input Amplitude 0.15 g0-pk
Alarm Levels ± 1 dB
Upper Abort Level 0.25 g0-pk
Lower Abort Level - 2 dB
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 11
Tower vib set up: Tower vib set up: Acceleromete
r. #Side-wall
Tray # LocationRead-out axis
1 +X 19 (top) +x, -y corner x
2 +X 19 (top) +x, +y corner z
3 +X 19 (top) +x, +y corner x
4 +X 10 Center of structural close-out x
5 +X1
(bottom)+x, +y corner z
6 +X1
(bottom)+x, +y corner x
7 +Y 19 (top) +y, -x corner y
8 +Y 10 Center of thermal boss y
9 +Y1
(bottom)+y, -x corner z
10 +Y1
(bottom)+y, -x corner y
11 -X 10 Center structural close-out x
12 -Y 10 Center of thermal boss plane y
13 - 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
cornery
16 - 1
(bottom)Center of the bottom side of the bottom tray z
Accelerometer locations
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 12
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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 13
Fixture calibrationFixture calibration
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 14
EM Tower vib sequence X,Y,Z axisEM Tower vib sequence X,Y,Z axisFor each axis
Run # Test Description Frequency Comments
1 Modal surveyInput: 0.15 g (20 – 2000
Hz)
2 Sinusoidal vibration 5 – 50 Hz Qual level
3 Modal surveyInput: 0.15 g (20 – 2000
Hz)
4 Random Vibration (-6 dB) Input 20 – 2000 Hz 1 min duration
5 Modal surveyInput: 0.15 g (20 – 2000
Hz)
6Random Vibration (- 3
dB)Input: 20 – 2000 Hz 1 min duration
7 Modal survey Input: 0.15 g 20 – 2000 Hz
8Random Vibration (Full
level)Input: 20 – 2000 Hz 1 min duration
9 Modal surveyInput: 0.15 g (20 – 2000
Hz)
10Random Vibration (Full
level)Input: 20 – 2000 Hz 2 min duration
11 Modal survey Input: 0.15 g (20 – 2000
Hz)
12 Sine burst (1/4 level) 25 Hz 5 cycles
13 Sine burst (1/2 level) 25 Hz 5 cycles
14 Sine burst (full level) 25 Hz 5 cycles
15 Modal SurveyInput: 0.15 g (20 – 2000
Hz)
GLAST LAT Project GSFC, October 2003
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EM matrixEM matrix
Item
Qu
antity
Qu
antity
to te
st
Sin
e b
urst (sta
tic eq
uiv
ale
nt
acce
lera
tion)
Random
Vib
e +
mod
al su
rvey
Sin
uso
idal v
ibra
tion
Functio
nal
Therm
al C
ycle
Therm
al b
ala
nce
Therm
al V
acu
um
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
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 16
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 …
GLAST LAT Project GSFC, October 2003
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Flight unitsFlight units
• New random level: Qual tower Protoflight tower
• Trays tower A vib level?
• Trays flight vib level?
GLAST LAT Project GSFC, October 2003
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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 1-16Acceptance
(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)
GLAST LAT Project GSFC, October 2003
LAT-PR-0XXXX 19
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