1 / 19

GLAST Large Area Telescope: EM Vibration Test Status Review

An outline of test strategies and initial results for the GLAST Large Area Telescope Tracker Subsystem INFN. Includes vibration and thermal test plans, with reference to essential LAT documents and test criteria. Key findings encompass resonance search, accelerometer positions, and vibration sequences for EM trays and towers. Discussion on test plans, procedures, and comparison of old and new vibration levels for tower qualification and acceptance.

geoff
Download Presentation

GLAST Large Area Telescope: EM Vibration Test Status Review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Gamma-ray Large Area Space Telescope Status of the EM Vib Tests GLAST Large Area Telescope:Tracker Subsystem INFN - Bari

  2. Outline • Test strategies • First results • Panel vib plan: tests done! • Tray thermal plan: tests to be done • Tower vib plan: ok plan and procedure ready for TRR, fixture calibration done, tower test to be done • Tower thermal-vacuum plan: TBR • EM Matrix plan • Reference LAT Documents: • LAT-MD-00408, LAT Instrument Performance Verification Plan • LAT-SS-00788, LAT Environmental Specification • LAT-TD-01005, Thermal Test Results on Thick Converter Mock-up Trays • LAT-TD-01249, Thermal Test Results for Pre-Engineering Model Trays • LAT-PS-01584, LAT Tracker TraySSD Ladder Panel Assembly Procedure • LAT-TD-01004, EM Tray Vibration Test Plan • LAT-TD-01037, EM Tray Thermal Test Plan

  3. EM Tray vib levels White Noise Sine sweep Random vibration

  4. Tray vib set up W side on the top • Accelerometers 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 V864LTshake table • 2 fixtures • 9 read out channels • 4 trays/day test rate capability

  5. EM Tray vib sequence thrust axis

  6. EM Trays: some results (1) Sine sweep before/after random Random vibration + White noise Z accelerometer response X accelerometer response Y accelerometer response Resonance search: 0= 815 Hz, Q  51 Resonance check: 0= 809 Hz, Q  49

  7. EM Trays: some results (2) Light ≈1000Hz ≈660Hz ≈ 800Hz Heavy tray Mid tray

  8. “Watch-dog” EM Trays: some results (3) Heavy tray (TS05) Q=100 @ 660Hz  Output-expected: 140.4 grms Applied notching on qual ASD: output ≤ 16 g2/Hz ( Q=10) “Watch-dog” Input-notched: 13.6 grms Output-notched: 59.6 grms

  9. / < 2% 530 EM Trays: summary Vib test pass criteria: / < 5% All trays first mode › 500 Hz

  10. EM Tower vib levels Sinusoidal vibration Sine burst: quasi static test@25Hz Modal survey Random vibration: new level

  11. Tower vib set up: Accelerometer locations

  12. Accelerometers location

  13. Fixture calibration

  14. EM Tower vib sequence X,Y,Z axis For each axis

  15. EM matrix

  16. Test plans & procedures: EM open items • 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 …

  17. Flight units • New random level: Qual tower  Protoflight tower • Trays tower A vib level? • Trays flight vib level?

  18. Towers: random levels New levels Old levels (general GEVS levels) Qualification (12.3 grms, 2 min) Workmanship (6.8 grms, 1 min) Tower A Qualification (14 grms, 2 min) Qualification ?? (14 grms, 2 min) Trays for tower A Acceptance (8.7 grms, 1 min) Workmanship (6.8 grms, 1 min) Towers 1-16 Acceptance (10 grms, 1 min) Acceptance ?? (10 grms, 2 min) Trays for towers 1-16

  19. Fast electrical test* Tower assembly Electrical test Stacked cosmic rays* Thermal cycles Vacuum bakeout Ladder factory Vibration test Tray factory (panels) Tray assembly: ladders and MCMs on trays Tray assembly&test sequence Plyform G&A Mipot Centrotecnica Roma G&A * Live trays

More Related