Bolt size (1) We are dealing with material where Yield strength and tensile strength are - PowerPoint Presentation

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Bolt size (1)

We are dealing with material where Yield strength and tensile strength are very close!

We need to pay attention to the Safety Factor!

Indian

supplier:

TorqBolt

 Inc

.

Solution under analysisBolt size (2)

Shear load for the bolts 1 V1 [N]

422Shear load for the bolts 2 V2 [N]

422Shear load for the bolts 3 V3 [N]362

Normal load for the bolts 1 S1 without preload [N]

430

Normal load for the bolts 2 S2 without preload [N]

362

Normal load for the bolts 3 S3 without preload [N]

430Normal load for the bolts 1 S1 with preload [N] 5784Normal load for the bolts 2 S2 with preload [N]5716Normal load for the bolts 3 S3 with preload [N]5784Moment load for the bolts 1 due to V M1 [Nmm]2111Moment load for the bolts 2 due to V M2 [Nmm]2111Moment load for the bolts 3 due to V M3 [Nmm]1811Check preload for shear 1: OK if > 1 (at warm)4.11Check preload for shear 3: OK if > 1 (at warm)4.06Check preload for shear 3: OK if > 1 (at warm)4.79Max Shear load for the bolts [N]422Max Normal load with preload for the bolts [N]5784Max Moment load for the bolts due to V [Nmm]2111

Shear stress for the bolts 1 τ1 [MPa]26.2Shear stress for the bolts 2 τ2 [MPa]26.2Shear stress for the bolts 3 τ3 [MPa]22.5Normal stress for the bolts 1 σ1 [MPa]26.7Normal stress for the bolts 2 σ2 [MPa]22.5Normal stress for the bolts 3 σ3 [MPa]26.7Bending stress for the bolts 1 σb1 [MPa]199.6Bending stress for the bolts 2 σb2 [MPa]199.6Bending stress for the bolts 3 σb3 [MPa]171.3Prestress σ0 [MPa]332Stress due to thermal contractio σth [MPa]24.2Combined stress σr1 [MPa]585Combined stress σr2 [MPa]581Combined stress σr3 [MPa]556Safety factor η11.42Safety factor η21.43Safety factor η31.49

Bolt MaterialTitanium gr. 5 Pitch p [mm]1Nominal diameter d [mm]6"Core" Bolt diameter d3 [mm]4.7731Outgassing hole diameter d [mm]1.5Bolt lenght L [mm]10Bolt length of the wolking thread Ld [mm]9Tensile stress area At [mm2]16.13Inertia of the Tensile stress area It [mm^4]25.23Corresponding bolt diameter in ANSYS d1 [mm]4.53Pretension constant K0.4Titanium gr 5 proof stress Sp [MPa]830Titanium gr. 5 Young's modulus E [MPa]110000Preload F [N]5354

Pressure Pr [MPa]0.18

Coefficient of static friction μ [-]

0.3

Bolt size (3)COMMENTS (2):

We decrease the preload in order to not stress too much the boltsIf the shear load is higher than the allowed one, we have a rigid body motion in the vessel between plates (stopped when the bolts touch the hole)If this happens, all the shear load is transferred on the weld seams

COMMENTS (1):Previous analyses have been preformed with friction coefficient equal to 0.3If I decrease the friction coefficient to 0.1, I need to increase the preload in order to have a SF(shear)=1.5 but I reduce the SF(bolts)

COMMENTS (3) about Stainless steel boltsThe huge stress due to differential thermal contraction decreases the SF(bolts). We need to further reduce the preload (down to 20%) in order to gain SF(bolts)=1.5

Stress due to thermal contractio σth [MPa]

284.7

Load casesQUESTION:

When should I add the pre-tuning effect? Others

QUESTION:Visit to Saclay (cryomodule assembly)?