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PST Design Update PST CDR october 2001

PST Design Update PST CDR october 2001. Current Design Status. FEA Modeling Design Variables Recent Analysis Results Low Stiffness Forwards SCT Reaction Loads Comparison to SCT analysis Testing Friction Tester Constructed Slider Materials Delivered Carbon Samples Ordered

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PST Design Update PST CDR october 2001

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  1. PST Design UpdatePST CDRoctober 2001 N. Hartman LBNL

  2. Current Design Status • FEA Modeling • Design Variables • Recent Analysis Results • Low Stiffness Forwards • SCT Reaction Loads • Comparison to SCT analysis • Testing • Friction Tester Constructed • Slider Materials Delivered • Carbon Samples Ordered • Prototyping Plans • One Foot Sample Mandrel will be fabricated • Initial Autoclave Tryout Run Will Be Completed Soon • Mandrel Quotes Received N. Hartman LBNL

  3. Design Variables • Flange Material (PEEK or Carbon Fiber) • Longitudinal Ribs • Hoop Stiffeners (in Forwards) • End Plug (PP1 panel) • Flange Shape • Barrel Constraints (ties across SCT diameter) • Service Mass (incorporated in forward shell material) • Fiberglass Forward Shells • 1 or 2 Z Constraints • Forward End Constraints N. Hartman LBNL

  4. PST Model N. Hartman LBNL

  5. FEA Model – Important Features 10 45 End Support 30 Hoop Hat Stiffeners (section view) Bolt flanges End Supports Sct mount pads End Plugs (1 mm equiv. carbon sheet) N. Hartman LBNL

  6. Flange x-section detail Support Tube – Flange Details End view of barrel flange (forward flanges have no Mount bosses and no gas seal features – see below) Constraint Areas forward barrel N. Hartman LBNL

  7. Flange Load L L/2 Flange Bolt Spacing Calculations Flange is conservatively modeled as a simple beam: - modeled as guided beam with length of bolt spacing/2 - cross section is assumed to be smallest flange section (forward) - flange force given by support tube loads (next slide) N. Hartman LBNL

  8. Flange Bolt Spacing Calculations (cont.) Flange load=(Forward Load*(L/d)) Forward Tube Flangedelta Barrel tube Assumed rigid d Forward And services mass L tube Deflection ( d ) Tube Deflection is calculated based on following assumptions: - forward tube pivots rigidly about bottom of flange - total forward tube mass (including services) is cantilevered - full flange load is taken by upper bolts only (3 bolts) - all structures rigid Frequency is estimated based on tube deflection using f=(1/2p * (g/d)1/2) desire frequency > 100 Hz number at left assumes no ribs -ribs act like bolt constraints -evenly spaced ribs allow half the number of bolts Design for 24 bolts in flange N. Hartman LBNL

  9. Support Flange Bonded Assembly Old design - now gone for independent thermal barrier Flange Face (machined layup) Stiffeners (layups) T-nuts (bonded) Flange base (Layup) N. Hartman LBNL

  10. PST Boundary Conditions N. Hartman LBNL

  11. +X +Z +Y Vertical Agreed Support Positions outside PST PST Support Conditions Under Investigation PST Position in Inner Detector Side C Side A ID Flat Rail View from top—all Tube Supports are Horizontal and Co-planar TRT SCT PIXEL SUPPORT TUBE Support Positions are shown, But constraint conditions are Not indicated here. ID Vee Rail Properties TBD Constraint TBD N. Hartman LBNL

  12. +X Fixed XYZ +Z Side C Barrel Side a +Y Vertical Fixed X Fixed Y Fixed Z Side C Barrel Side a Constraint Conditions: Fixed/Free ends Fixed Forward Ends Free Forward Ends N. Hartman LBNL

  13. Material Model Material Location Fiber Modulus (GPa) Bulk Modulus (GPa) Density (kg/m3) High Mod. Carbon Shell, Hat Stiffeners 420 98 1650 Ultra High Mod. Carbon Flanges (Option 1) 560 126 1650 PEEK (graphite filled) Flanges (Option 2) N/A 3.5 1500 Glass (Quartz) Forward Shells 91 21 1800 HM Carbon (incl. service mass) Forward Shells 420 98 12300 Glass (incl. service mass) Forward Shells 91 21 12450 Model Properties N. Hartman LBNL

  14. PST Analyses N. Hartman LBNL

  15. Side C Barrel Side a Side C Barrel Side a Original Model PEEK Flanges Longitudinal Ribs N. Hartman LBNL

  16. Side C Barrel Side a Side C Barrel Side a Carbon Flange Material Carbon Flanges Longitudinal Ribs N. Hartman LBNL

  17. Side C Barrel Side a Side C Barrel Side a Removing Ribs No Longitudinal Ribs N. Hartman LBNL

  18. Side C Barrel Side a Constrain across SCT Side C Barrel Side a N. Hartman LBNL

  19. Modal Shapes Hoops and End Plugs New Flange Shape Barrel Constraints Modes: 119 / 119 / 124 / 124 N. Hartman LBNL

  20. Low Stiffness Forwards Additional Hoops N. Hartman LBNL

  21. Vibration Results Summary N. Hartman LBNL

  22. Model Material Both Ends Bent – 1 Z Constraint FX (N) FY (N) FZ (N) MX (Nm) MY (Nm) MZ (Nm) Model Material FX (N) FY (N) FZ (N) MX (Nm) MY (Nm) MZ (Nm) Carbon - 151 0 253 - - Carbon 146 - - - 233 - Glass - 53 0 89 - - Glass 52 - - - 83 - Both Ends Bent – 2 Z Constraints Model Material FX (N) FY (N) FZ (N) MX (Nm) MY (Nm) MZ (Nm) Carbon 297 - 1870 - 536 - Glass 108 - 468 - 110 - One End Bent – 1 Z Constraint Model Material FX (N) FY (N) FZ (N) MX (Nm) MY (Nm) MZ (Nm) Carbon 390 - - - 623 - Glass 137 - - - 218 - Reaction Loads On SCT Vertical Bending – Both Ends Horizontal Bending N. Hartman LBNL

  23. Gravity Sag Calculations Carbon Glass DY = .57 mm DY = 1.6 mm N. Hartman LBNL

  24. Comparison to SCT Analyses • Discrepancies Due To: • Properties (SCT used different tube modulus; barrel modulus and forward modulus changed to glass) • Loads (pixel detector distributed, not supported on mounts) • Constraints • Extra Z constraint • SCT intrinsic compliance • Simple instead of complete constraints at Barrel Projected uses ratio of SCT to our FEA with carbon forward tubes N. Hartman LBNL

  25. Slider design - materials testing • Friction Tester nearing completion • Applies variable pressure • Measures angular acceleration • Slides sample against interchangeable disk of given material Mass provides normal force position is movable along arm M arm hinge turntable (carbon disk) slider to be tested Encoder on shaft measures acceleration M G N. Hartman LBNL

  26. Materials to Be Tested • Sliding Materials • PEEK • Glass Filled • Virgin • Vespel • Moly-Disulfide Filled • Virgin • PPS • Teflon, Carbon, glass, moly-disulfide filled • Probably not viable • Substrates • Carbon fiber disks (prospective material and Layup) • 420 GPa Fiber • 8 Ply Quasi-iso layup • 437 micron thickness • Non-Woven glass mat on surface (some samples) • Work just starting. No conclusions. May investigate roller depending upon results N. Hartman LBNL

  27. Prototyping Plans • Short Mandrel • 1 foot long - 1 for glass, 1 for carbon – aluminum or steel • “Dry-run” in autoclave to determine thermal response • Determine final diameters from test layups • Full Size Mandrel (forward length) • Quotes already received • Approximately 14,000 to 20,000 USD • 8 Weeks delivery • Plans to Fabricate forward prototype in glass • All flanges and rail features • Use for production forwards if diameters are correct • Implications of Glass Forwards/Carbon Barrel on prototyping plans must be assessed N. Hartman LBNL

  28. Plans For Near Future • Import SCT Model into current analyses • Double check SCT loads – ascertain acceptability • Determine pixel stability with reduced stiffnesses • Begin detailed design of flanges and tubes • Fabricate sample tube sections (1 foot lengths) • Analyze mounts/end constraints/service interactions • Eric Anderssen’s presentation N. Hartman LBNL

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