DFBX ThermoMechanical Review Joseph Rasson LBL Tom Peterson

DFBX Thermo-Mechanical Review Joseph Rasson, LBL Tom Peterson, Fermilab CERN 24 April 2007 DFBX

DFBX Presentation Outline • • • Introduction Documentation Flow schematic Line pressures Mechanical Test Protocol Piping and Interface Layouts Mechanical Loads Free body and force diagrams Peak stresses Transport Conclusion Future Activities 24 April 2007 DFBX 2

Introduction • DFBX designed at LBNL and fabricated at Meyer Tool near Chicago Illinois • Fabrication oversight performed by Fermilab • Present team consists of – – – Joseph Rasson (LBL), project manager Steve Virostek (LBL), engineer Frederic Gicquel (LBL @ CERN), engineer Tom Peterson (Fermilab), engineer Phil Pfund (Fermilab), engineer 24 April 2007 DFBX 3

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DFBX Documentation • http: //www-td. fnal. gov/LHC/Uslhc_accel_docs/Documents. html – Fabrication documentations for DFBX and LQX. • http: //sc-gs. web. cern. ch/sc-gs/gs_ms/TISUS/ – Safety related documentation submitted to CERN. • http: //tomato. fnal. gov/lhcirq/DFBXimages/Index. DFBX. html – Pictures of DFBX during fabrication at the vendor. • http: //www-eng. lbl. gov/~rasson/DFBX%20 DWGS_APRIL_07/ – Drawings of the DFBX. 24 April 2007 DFBX 7

Flow schematic • The inner triplet cryogenic flow schematic was developed in close collaboration between – Rob Van Weelderen (CERN) – Jon Zbasnik (LBL) – Tom Peterson (Fermilab). • The following are excerpts from the DFBX G/C and DFBX E flow schemes. 24 April 2007 DFBX 8

Overview of DFBX Flow Schemes • 8 DFBX’s, 6 different types – QRL on wall side, so left and right at each location differ in being “left handed” and “right handed” – Points 2 and 8 have the same configuration with cold D 1, so DFBX C is identical to G and DFBX D is identical to H. – Points 1 and 5 differ from 2 and 8 in having warm D 1 and differ from each other in having opposite slopes. 24 April 2007 DFBX 9

Flow schematic for IP 8 left Following slide shows the DFBXG detail 24 April 2007 DFBX 10

DFBX-G lines with 20 bar design (the largest high-pressure lines) Helium vessel 24 April 2007 DFBX 11

Flow schematic for IP 5 left Following slide shows the DFBXE detail 24 April 2007 DFBX 12

DFBX-E lines with 20 bar design (the largest high-pressure lines) Helium vessel 24 April 2007 DFBX 13

Pressures Reference: LHC Project Note 135 24 April 2007 DFBX 14

Mechanical Test Protocol Tests at the manufacturer (Doc. M 989 A): • Cold shock all welds at least one cycle • Cold shock chimney bellows 25 cycles • Pressure test all components at set test pressure • Vacuum leak check all components • Final system pressure test and vacuum leak check • Measurements of all critical dimensions Vacuum leak checks and measurement of critical dimensions were repeated at CERN after shipping: See Doc LHC-DFBX-001 -10 -00 24 April 2007 DFBX 15

DFBX Piping Layout D 1 End Q 3 End 24 April 2007 DFBX 16

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DFBX – Q 3 Interface 24 April 2007 DFBX 18

DFBX – Q 3 Interface 24 April 2007 DFBX 19

Mechanical Loads • Mechanical loads on the DFBX are Generated from: – Thermal contraction of spool pieces and magnets – Thrust load from bellows (positive and vacuum pressures) – Internal pressure (positive and vacuum pressures) – Gravitational loads (weight) 24 April 2007 DFBX 20

Forces from Thermal Contractions • Dominated by contraction of magnet ends away from DFBX – Q 3 lines pull back 16. 3 mm – D 1 lines pull back ~20 mm D 1 fixed support at Center • Internal DFBX components: Max thermal contractions is ~ 6 mm • Design Approach: Neutralize mechanical forces generated from thermal contraction with the use of flex hoses 24 April 2007 DFBX 21

Design Approach for Thermal Contraction Welded ring to carry weight of pipe on G 10 Spider Assy Flex hoses to take up thermal contraction Pipes are installed such as flex hoses are preflexed half way when warm. Flexhose moves +/ - thermal contraction length and pipe misalignment 24 April 2007 DFBX 22

Welded ring to carry weight of pipe on G 10 Spider Assy Large diameter flex hose: 50. 8 mm Dia 24 April 2007 DFBX 23

Gravitational Loads • Weight of most spool pieces is supported on G 10 spiders in jumpers • Spiders also provide mean to keep the pipes aligned during and after interconnection • Weight of LHe vessel and bus ducts is transferred to vacuum vessel via 4 - 19 mm invar rods (to be discussed later) 24 April 2007 DFBX 24

Double spiders in jumpers carry the weights of small pipes and guide/align pipes 12. 7 mm thick G 10 plates 6. 4 mm mm thick G 10 split Pipes 24 April 2007 DFBX 25

Non Load Bearing G 10 Support Spiders D 1 End 22. 2 mm thick G 10 plate 12. 7 mm thick G 10 plates Q 3 End Beam pipe Center support Attached to LHe vessel Bus duct SS support clamps and split rings 24 April 2007 DFBX 26

Thrust Loads in DFBX • Limited to components with bellows at the ends for ease of interconnect and to allow for thermal contraction: • • XB: Q 3 -DFBX pumping line MQX 1: Q 3 -DFBX bus duct MBX 1: D 1 -DFBX bus duct LD cross-over line inside the box whenever we have cold D 1 (4 boxes) 24 April 2007 DFBX 27

DFBX Thrust Loads English Units Si Units Line D mean (in) Pres Design (bar) F (lb) XB 4. 45 4 MQX 1 4. 45 MBX 1 LD 24 April 2007 Line D mean (mm) Pre Design (bar) F (N) 902 XB 113. 0 4 4012 20 4510 MQX 1 113. 0 20 20062 3. 16 20 2274 MBX 1 80. 4 20 10116 2. 54 20 1469 LD 64. 5 20 6536 DFBX 28

XB Line with Flow Separator D 1 20 mm Thermal contraction Flex hose for alignment Flex hose for thermal contraction Q 3 -XB Thrust: 4 KN 24 April 2007 DFBX 29

3 Gravity Vertical Supports XB Supports 2 Thrust Supports to vacuum vessel 24 April 2007 DFBX 30

XB without Flow Separator 2 Horizontal Thrust Supports One gravitational support 24 April 2007 DFBX 31

Bus Duct Assembly: Thrust Load D 1: 10. 1 KN LD: 6. 5 KN Q 3: 20 KN 24 April 2007 Thrust Support Brackets DFBX 32

LHe Vessel Support 24 April 2007 DFBX 33

End view showing helium vessel axial supports and beam tube support 24 April 2007 DFBX 34

LHe Vessel Bottom Support to Vacuum Plate 24 April 2007 DFBX 35

DFBX-E 17 Feb 05 24 April 2007 DFBX 36

Free Body Diagrams • General diagrams showing approximate magnitude of force • More detailed analysis will be presented at the component level 24 April 2007 DFBX 37

Forces on DFBX-E due to pressure of 3. 5 bar in the helium vessel plus gravity 66. 8 k. N (15000 lbf) 635 mm (25. 0 in) 767 mm (30. 2 in) 16. 7 k. N (3750 lbf) x 2 (rods in tension) 24 April 2007 16. 7 k. N (3750 lbf) x 2 (rods in tension) DFBX 38

Forces on DFBX-E due to M 1 line pressure of 20 bar plus gravity (no helium vessel pressure) 4. 4 k. N (1000 lbf) 3. 0 k. N (680 lbf) x 2 (rods in compression) 635 mm (25. 0 in) 10. 0 k. N (2250 lbf) x 2 20. 0 k. N (4500 lbf) 767 mm (30. 2 in) 5. 4 k. N (1180 lbf) x 2 (rods in tension) 24 April 2007 DFBX 39

Forces on DFBX-E due to 20 bar M 1 line pressure plus 3. 5 bar in the helium vessel 66. 8 k. N (15000 lbf) (Combined pressure and gravity) 635 mm (25. 0 in) 10. 0 k. N (2250 lbf) x 2 20. 0 k. N (4500 lbf) 767 mm (30. 2 in) 20. 8 k. N (4680 lbf) x 2 (rods in tension) 24 April 2007 12. 5 k. N (2820 lbf) x 2 (rods in tension) DFBX 40

Forces on DFBX-C due to 20 bar M 1 line pressure plus 3. 5 bar in the helium vessel 82. 3 k. N (18500 lbf) (Combined pressure and gravity) 10. 1 k. N ( 2280 lbf) 635 mm (25. 0 in) 5. 0 k. N (1110 lbf) x 2 20. 0 k. N (4500 lbf) 767 mm (30. 2 in) 22. 6 k. N (5090 lbf) x 2 (rods in tension) 24 April 2007 18. 5 k. N (4170 lbf) x 2 (rods in tension) DFBX 41

Forces on DFBX-C due to 3. 5 bar in the helium vessel 82. 3 k. N (18500 lbf) 635 mm (25. 0 in) 767 mm (30. 2 in) 24 April 2007 20. 6 k. N (4630 lbf) x 2 (rods in tension) DFBX 20. 6 k. N (4630 lbf) x 2 (rods in tension) 42

DFBX Detailed Analysis • Analysis assumptions and methodology • He vessel supports - stress analysis • Upper, vertical support rods and attachments • Lower, axial supports and attachments • He vessel cover plate weld – stress analysis • Bus duct & thrust support – stress analysis • XB line – load and stress analysis • Vacuum Vessel Bumpers 24 April 2007 DFBX

Analysis Assumptions and Methodology • Analyses assume worst case operating loads • 3. 5 bar absolute in helium vessel • 20. 1 k. N (4510 lb) bus duct thrust load (20 bar) • XB line thrust • 4. 0 k. N (902 lb) thrust load (4 bar) • Possible added load from D 1 line • All components are assessed based on the material and weld allowable limits set forth by the ASME Pressure Vessel Code • Code limits are for guidance and not a hard requirement 24 April 2007 DFBX

Helium Vessel Support Loads • Reaction loads are based on the results of the helium vessel FEA model runs • A portion of the bus duct thrust load is reacted at the stack bellows due to their high lateral stiffness • Vertical strut loads are affected by the moment from bus duct thrust load • The worst case vertical support rod and axial support loads are used for all analyses • Peak axial support load: 8. 7 k. N (1962 lb) • Peak strut tensile load (Q 3 side): 15. 9 k. N (3570 lb) • Peak strut tensile load (D 1 side): 19. 6 k. N (4414 lb) 24 April 2007 DFBX • Peak strut compressive load: 3. 03 k. N (682 lb)

Pressure Vessel Code Stress Limits • Material stress allowable limits from code • SS 304 L: 115 MPa (16. 7 ksi) tensile stress • SS 18 -8: 130 MPa (18. 8 ksi) tensile stress • Invar: 276 MPa (40 ksi) yield stress (not from code) • PV code limits have built-in safety factors • S. F. ~2 on yield and >4 on ultimate stress • For welds, efficiency factors are applied based on guidelines in PV code • Tensile and shear stresses are combined using von Mises formulation 24 April 2007 DFBX

Lower He Vessel Axial Load Blocks (weld) Calculation Details Material: 304 L stainless steel Net axial load: 8. 7 k. N (1962 lb) Weld size: 9. 65 mm (0. 38”) Moment arm: 36 mm (1. 4”) Weld A: 1560 mm 2 (2. 42 in 2) Weld I: 4. 40 x 105 mm 4 (1. 06 in 4) Tensile stress: 13. 4 MPa (1. 95 ksi) Shear stress: 5. 6 MPa (0. 81 ksi) Equivalent stress: 16. 6 MPa (2. 40 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) 24 April 2007 DFBX Weld

Lower He Vessel Axial Load Blocks (mat’l) Calculation Details Material: 304 L stainless steel Net axial load: 8. 7 k. N (1962 lb) Moment arm: 36 mm (1. 4”) Block A: 2903 mm 2 (4. 50 in 2) Block I: 3. 51 x 105 mm 4 (0. 84 in 4) Tensile stress: 16. 8 MPa (2. 44 ksi) Shear stress: 3. 0 MPa (0. 44 ksi) Equivalent stress: 17. 6 MPa (2. 56 ksi) Allowable stress: 115 MPa (16. 7 ksi) 24 April 2007 DFBX

Lower He Vessel Invar Rods and Nuts Rod Calculation Details Material: Invar ½” all thread Net axial load: 4. 4 k. N (981 lb) Rod stress area: 91. 5 mm 2 (0. 142 in 2) Tensile stress: 47. 7 MPa (6. 91 ksi) Yield stress: 276 MPa (40 ksi) Nut Calculation Details Material: 18 -8 stainless steel Net axial load: 4. 4 k. N (981 lb) Nut shear stress area: 211 mm 2 (0. 33 in 2) (based on load carried by 3 threads) Equivalent stress: 35. 9 MPa (5. 21 ksi) Allowable stress: 130 MPa (18. 8 ksi) 24 April 2007 DFBX Assume load is shared equally on both sides of 2 -sided rod Both rods and nuts can carry the full load at one end of the rod if machining and assembly tolerances lead to unequal loading

Lower He Vessel Axial Stanchions Calculation Details Material: 304 L stainless steel Net axial load: 4. 4 k. N (981 lb) Moment arm: 95 mm (3. 8”) Area: 1976 mm 2 (3. 06 in 2) Mom. area I: 3. 25 x 105 mm 4 (0. 78 in 4) Bending stress: 28. 4 MPa (4. 12 ksi) Shear stress: 2. 2 MPa (320 psi) Equivalent stress: 28. 7 MPa (4. 16 ksi) Allowable stress: 115 MPa (16. 7 ksi) Peak Stress One stanchion carry the full load if machining and assembly tolerances lead to unequal loading 24 April 2007 DFBX

Lower He Vessel Axial Stanchion Bolts Bolt Stress Calculation Details Material: 18 -8 stainless steel Bolt size: M 16 -1 Assume tensile and shear carried by 1 bolt Axial force due to moment: 4. 7 k. N (1065 lb) Stress area: 175 mm 2 (0. 27 in 2) Tensile stress: 27. 1 MPa (3. 93 ksi) Shear stress: 25. 0 MPa (3. 62 ksi) Equivalent stress: 51. 0 MPa (7. 40 ksi) Allowable stress: 130 MPa (18. 8 ksi) One bolt in one stanchion carry the full load if machining and assembly tolerances lead to unequal loading 24 April 2007 DFBX Thread Engagement Details Bolt length: 45 mm Stanchion thickness: 25. 4 mm G-10 shim thickness: 3. 3 mm Washer thickness: 3. 0 mm Net thread engagement: 13. 3 mm No. engaged threads: 13 Minimum threads required: 3 to 5

Lower He Vessel Axial Stanchion Friction Calculation Details Material: 18 -8 stainless steel Bolt size: M 16 -1 Stress area: 175 mm 2 (0. 27 in 2) Yield stress: 276 MPa (40 ksi) Bolt load: 24. 1 k. N (5420 lb) @ 50% yield Force per stanchion: 48. 2 k. N (10. 8 k-lb) Coefficient of friction: 0. 4 (G-10/SS) Static friction force: 19. 3 k. N (4336 lb) Axial stanchion force: 4. 4 k. N (981 lb) • Friction force is sufficient to prevent slipping, even if the full force on one side acts on a single stanchion • If slipping occurs due to low bolt torque, motion is limited to 0. 75 mm radial clearance on bolt holes • Stanchions, full force on one side 24 April 2007 bolts and rods can handle. DFBX

He Vessel Clevises for Vertical Struts (weld) Calculation Details Material: 304 L stainless steel Maximum strut load: 19. 6 k. N (4414 lb) Weld size: 12. 7 mm (0. 50”) Moment arm: 59 mm (2. 31”) (longer clevis) Weld A: 1866 mm 2 (2. 89 in 2) Weld I: 10. 4 x 105 mm 4 (2. 50 in 4) Tensile stress: 31. 7 MPa (4. 60 ksi) Shear stress: 10. 5 MPa (1. 53 ksi) Equivalent stress: 36. 6 MPa (5. 31 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) 24 April 2007 DFBX Weld

He Vessel Clevises for Vertical Struts (mat’l) Analysis Parameters Material: 304 L stainless steel Maximum strut load: 26. 7 k. N (6005 lb) Allowable stress: 115 MPa (16. 7 ksi) Shear Pullout Calculation Details Shear pullout area: 317 mm 2 (0. 49 in 2) (load spread over 4 areas at each clevis) Shear stress: 15. 5 MPa (2. 25 ksi) Equivalent stress: 26. 8 MPa (3. 89 ksi) Clevis Bending Stress Calculation Moment arm: 24 mm (0. 94”) (at base of rod end cut-out) Area: 1288 mm 2 (2. 00 in 2) Clevis Pin Calculation Details Mom area I: 1. 76 x 105 mm 4 (0. 43 in 4) Pin diameter: 19. 1 mm (0. 75 in) Bending stress: 76. 1 MPa (11. 0 ksi) Pin area: 285 mm 2 (0. 442 in 2) Shear stress: 15. 2 MPa (2. 21 ksi) Shear stress: 34. 4 MPa (5. 00 ksi) Equivalent stress: 59. 7 MPa (8. 65 ksi) DFBX Equivalent stress: 80. 6 MPa (11. 7 ksi) 24 April 2007 (load shared over 2 clevis sides)

He Vessel Vertical Support Struts Strut Body Stress Calculation Details Material: Invar End thread size: ¾”-16 UNF Peak axial force: 26. 7 k. N (6005 lb) Thread stress area: 241 mm 2 (0. 373 in 2) Tensile stress: 81. 6 MPa (11. 8 ksi) Yield stress: 276 MPa (40 ksi) Strut Buckling Analysis Material: Invar Modulus: 141 GPa (20. 5 Mpsi) Rod diameter: 19. 1 mm (0. 75”) Mom. area I: 0. 647 x 105 mm 4 (0. 016 in 4) Rod length: 760 mm (29. 1”) (pinned ends) Peak compressive force: 3. 03 k. N (682 lb) 24 April 2007 DFBX Critical load: 15. 6 k. N (3513 lb) Tension In Strut Rod Ends Rod end: Aurora ¾” S-12 Peak load: 19. 6 k. N (4414 lb) Allowable load: 32. 7 k. N (7364 lb)

He Vessel Top Plate Support (horiz wall weld) L-bracket Weld Calculation Details Material: 304 L stainless steel Maximum strut load: 19. 6 k. N (4414 lb) Weld size: 6. 35 mm (0. 25”) Block depth: 64 mm (2. 5”) Block width: 38 mm (1. 5”) Moment arm: 19. 1 mm (0. 75”) Weld A: 912 mm 2 (1. 41 in 2) Weld I: 5. 36 x 105 mm 4 (1. 29 in 4) Tensile stress: 21. 5 MPa (3. 12 ksi) Bending stress: 22. 1 MPa (3. 21 ksi) Equivalent stress: 43. 7 MPa (6. 33 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) 24 April 2007 DFBX

Vessel Top Plate Support (horiz wall bracket) Added Clevis Weld Calculation Details Material: 304 L stainless steel Maximum strut load: 19. 6 k. N (4414 lb) Weld size: 6. 35 mm (0. 25”) Weld length: 38 mm (1. 5”) # of welds per support: 4 Weld area: 684 mm 2 (1. 06 in 2) total Shear stress: 28. 7 MPa (4. 16 ksi) Equivalent stress: 49. 7 MPa (7. 21 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) Clevis Shear Pullout Calculation Details Shear pullout area: 242 mm 2 (0. 375 in 2) Shear stress: 27. 6 MPa (4. 00 ksi) (load spread 24 April 2007 over 4 areas at each clevis) DFBX Equivalent stress: 35. 1 MPa (5. 10 ksi) Welds Added clevis Bolt

He Vessel Top Plate Support (vertical wall) Boss Weld Stress Calculation Details Material: 304 L stainless steel Maximum strut load: 15. 9 k. N (3570 lb) Weld size: 12. 7 mm (0. 50”) Moment arm: 64 mm (2. 50”) w/adapter Weld A: 1328 mm 2 (2. 06 in 2) Weld I: 3. 81 x 105 mm 4 (0. 916 in 4) Tensile stress: 50. 4 MPa (7. 31 ksi) Shear stress: 12. 0 MPa (1. 73 ksi) Equivalent stress: 54. 5 MPa (7. 90 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) Clevis Shear Pullout Same shear area as horizontal wall support with a lower load 24 April 2007 DFBX

Helium Vessel Cover Plate Weld Analysis • Vessel cover plate is welded to frame using a single, continuous external fillet weld • Allows for cover removal by grinding if access is needed • This weld type is an exception to ASME pressure vessel code • A 2 D finite element model predicts the actual weld stresses to allow exception to code • Allowable stress is exceeded only in very small zone at the root of the 24 April 2007 DFBX weld (root stress < yield stress) Cover Weld Vessel frame

Bus Duct Thrust Support Thrust Load Weld Clamp Thrust Support Plate Welded to LHe Vessel 24 April 2007 DFBX 60

Bus duct thrust support “Weld Clamp” Support Bracket 24 April 2007 DFBX 61

Bus Duct Thrust Support Analysis (weld clamp) Weld Clamp Stress Calculation Details Material: 304 L stainless steel Peak thrust load: 20. 1 k. N (4510 lb) Weld size: 1. 59 mm (1/16”) 2 sides of clamp Weld diameter: 48. 3 mm (1. 90”) Shear stress: 61. 5 MPa (8. 92 ksi) Equivalent stress: 107 MPa (15. 4 ksi) Weld clamp Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) Weld stress exceeds allowable stress dictated by PV code but is still within material strength limits 24 April 2007 Thrust support DFBX

Bus Duct Thrust Support (thrust plate weld) Thrust Plate Weld Stress Calculation Material: 304 L stainless steel Peak thrust load: 20. 1 k. N (4510 lb) Weld size: 6. 35 mm (1/4”) Weld area: 940 mm 2 (1. 46 in 2) Weld mom. Area I: 1. 61 x 105 mm 4 (0. 388 in 4) Equivalent stress: 106 MPa (15. 4 ksi) Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net allowable stress: 63. 3 MPa (9. 19 ksi) Weld stress exceeds allowable stress dictated by PV code but is still within material strength limits 24 April 2007 DFBX Thrust plate

Q 3 Side - Bus Duct Thrust Support (thrust plate bending) Thrust Plate Bending Stress Calculation Material: 304 L stainless steel Peak axial load: 20. 1 k. N (4510 lb) Plate thickness: 12. 7 mm (0. 5”) Ears Moment arm: 57. 2 mm (2. 25”) Area: 1787 mm 2 (2. 77 in 2) Mom area I: 2. 40 x 104 mm 4 (0. 058 in 4) Bending stress: 304 MPa (44. 0 ksi) Thrust Shear stress: 11. 2 MPa (1. 63 ksi) plate Equivalent stress: 304 MPa (44. 1 ksi) Weld Clamp Ear Stress Results Allowable stress: 115 MPa (16. 7 ksi) Equivalent stress: 127 MPa (18. 4 ksi)* Plate stress exceeds material strength limits – thrust support plate needs reinforcement 24 April 2007 Thrust Plate Ear Stress Results Equivalent stress: 146 MPa (21. 2 ksi)* DFBX * Both exceed PV code but are < yield

Bus Duct Thrust Support (D 1 side) Thrust Plate Bending Stress Calculation Material: 304 L stainless steel Peak axial load: 10. 1 k. N (2274 lb) Plate thickness: 12. 7 mm (0. 5”) Moment arm: 46. 0 mm (2. 25”) Area: 1787 mm 2 (2. 77 in 2) Mom area I: 2. 40 x 104 mm 4 (0. 058 in 4) Bending stress: 123 MPa (17. 9 ksi) Shear stress: 11. 2 MPa (1. 63 ksi) Equivalent stress: 125 MPa (18. 1 ksi) Allowable stress: 115 MPa (16. 7 ksi) Material stress exceeds allowable stress dictated by PV code but is well within material strength limits 24 April 2007 Thrust plate Short, double Plate design DFBX

XB Line/Surge Tank Load Analysis • XB pipe and surge tank uses 3 vertical and 2 horizontal stainless rods to resist thrust loading . 65 k. N 4. 0 k. N 3. 4 k. N • A simple FEA model using beam elements was used to determine the support reaction forces • Loads: XB bellows thrust (4. 0 k. N), D 1 line force (0. 44 k. N), gravity and thermal contraction • Assume that rods do not support large moments due to pivoting at ends and localized yielding (i. e. forces in rods are essentially. DFBX axial) 24 April 2007 1. 0 k. N . 80 k. N . 65 k. N 3. 4 k. N 4. 0 k. N . 44 k. N

XB Line/Surge Tank Stress Analysis Axial Support Rods Material: 18 -8 stainless steel Peak axial load: 3. 4 k. N (770 lb) Equivalent stress: 68. 5 MPa (9. 9 ksi) Allowable stress: 130 MPa (18. 8 ksi) Surge tank brackets Material: 304 L stainless steel Weld size: 2. 8 mm (0. 11”) Peak vertical load: 1. 0 k. N (233 lb) Equivalent stress: 25. 0 MPa (3. 62 ksi) Peak horizontal load: 0. 80 k. N (179 lb) Equivalent stress: 14. 9 MPa (2. 16 ksi) 1. 0 k. N 3. 4 k. N (worst case axial rod load) 1. 0 k. N Worst case vertical tab weld load Allowable stress: 115 MPa (16. 7 ksi) Weld efficiency factor: 0. 55 Net 24 allowable April 2007 stress: 63. 3 MPa (9. 19 ksi) DFBX . 80 k. N Horizontal supp’t weld load

XB Line/Surge Tank Stress Analysis Forked Bracket Bending Stress Calculation Material: 304 L stainless steel Peak axial load: 3. 4 k. N (770 lb) 3. 4 k. N (worst case Plate thickness: 12. 7 mm (0. 5”) axial rod load) Moment arm: 31. 8 mm (1. 25”) Area: 403 mm 2 (0. 625 in 2) Mom area I: 5. 42 x 103 mm 4 (0. 013 in 4) Bending stress: 127 MPa (18. 5 ksi) Tensile stress: 8. 5 MPa (1. 23 ksi) Equivalent stress: 136 MPa (19. 7 ksi) Allowable stress: 115 MPa (16. 7 ksi) Material stress exceeds allowable stress dictated by PV code but is well within material strength limits 24 April 2007 DFBX Bending stress on forked bracket 3. 4 k. N

XB Line (w/o surge tank) Load Analysis • XB pipe (w/o tank) uses 1 vertical and 2 horizontal rods to resist thrust loading • Load centered on the 2 horizontal supp’ts • Rod loading less than case with surge tank 0. 2 k. N 2. 0 k. N Circular Plate Bending Stress Calculation Material: 304 L stainless steel 2. 0 k. N Support load: 2. 2 k. N (501 lb) Plate thickness: 9. 5 mm (0. 375”) 4. 0 k. N Circular Moment arm: 114 mm (4. 5”) thrust Area: 1089 mm 2 (1. 69 in 2) plate 3 4 4 Mom area I: 8. 23 x 10 mm (0. 020 in ) Bending stress: 147 MPa (21. 4 ksi) Material stress exceeds allowable Shear stress: 2. 0 MPa (0. 30 ksi) stress dictated by PV code but is Equivalent stress: 147 MPa (21. 4 ksi) within material strength limits 24 April 2007 DFBX Allowable stress: 115 MPa (16. 7 ksi)

Bumpers Worst case scenario: -Warm D 1 -jacks on IT fully react load -jacks on DFBX do not react load => full vacuum load 19540 lb (87 k. N) on 2 bumpers Prying force (spread on 2 anchors): F=13/10*9770=12701 lb (56. 5 k. N) => 6350 lb per anchor 9770 lb (43. 5 k. N) Shear force (spread on 4 anchors): F=9770 lb (43. 5 k. N) => 2442. 5 lb per anchor 13” Hilti anchors HSL M 24/60 Allowable working load in Tension 9860 lb (43. 8 k. N) Allowable working load in shear 17950 lb (79. 8 k. N) Stand offs rated at 20000 lb each 24 April 2007 Prying force 10” Pivot point DFBX 70

Bumper FEA model Local Max stresses at 136 MPa Yield at 190 Mpa 24 April 2007 DFBX 71

DFBX Shipping The DFBX were shipped in pairs, each in its own three-piece shipping frame Boxes C being placed in base of shipping frame. Shock recorders have been mounted on each side of frame (one visible on this side). Two more are mounted on the top plate of DFBX. Boxes C & G at CERN. One of two shock recorder mounted on frame is shown in insert. Another is mounted on the other side and two are mounted on the top plate of each DFBX. 24 April 2007 DFBX 72

DFBX Summary • Detailed analyses were performed during design phase based CERN requirements • Continued oversight during the fabrication phase to insure that specifications were met • Cold shocks, pressure tests and vacuum leak checks were performed at the component level at the manufacturer and CERN • Analysis confirmed that the LHe vessel structure is robust • During the last month the DFBX mechanical structure was reviewed and much of it was analyzed – FNAL organized two peer reviews 24 April 2007 DFBX 73

DFBX Conclusion • The analysis confirmed that the bus duct thrust support is marginal – “Weld Clamp” was not welded – Support bracket is too thin • Review and analysis of other components of the box revealed additional that should be upgraded – Eliminate LHe vessel vertical rods linkage dependence on friction generated by bolt tightness 24 April 2007 DFBX 74

Future Activities • Continue reviewing and analyzing key aspect of DFBX as built • Design and implement improved bust duct support • Perform simulated thrust load tests • Review of all cooldown and warmup conditions to look for potential interferences 24 April 2007 DFBX 75