Vacuum Vessel lateral loading (Neutral beam port only)

5-12-05

Assumptions

• Vacuum pressure loading on neutral beam transition duct is omitted.

• Lateral support bracket is far from the neutral beam port flange. Thus, the port flange is fixed in this model and only local stress/deformation effects near the bracket are analyzed.

• Magnetic disruption loads assumed are 7000 lbs lateral distributed evenly between two neutral beam ports (3500 each).

• Vacuum loading due to unbalanced atmospheric load from two 12” diameter pumping ducts on one neutral beam port is considered. This results in a load (15 psi *π*12”^2/4 = 1696 lb) applied on the neutral beam port lateral support.

Model

Refined mesh near lateral support bracketOnly Neutral beam is modeled

Loading

• Fv = Vacuum Vessel unbalanced atmospheric load due to bellows on the neutral beam port.

• Fl = Vacuum vessel dynamic loading due to the magnetic disruption and/or seismic loading

• Fr = Resultant load on the NBTD lateral support bracket due to Fv and Fl.

NBTB

Bellows

Fv (Vacuum Load)

Fl (VV Lateral Load)

NBTD Lateral Support Bracket

FrFr

NBTD Lateral Support Bracket

30.0°

Fv VV unbalanced atmospheric load due to vacuum bellows on NBTD. Fl VV dynamic loading due to magnetic disruption and/or seismic loading. Fr Resultant load on the NBTD lateral support bracket

MC Bracket

Loading on FEA model

• The 6098 lb force applied to the lateral support bracket is a combination of the lateral magnetic (4140 lbs) loading and the vacuum loading (estimated at 1958 lbs)

• Model is fixed on the vacuum vessel flange support.

• Standard Earth Gravity is applied.

• All parts are constructed of Inconel 625.

• The bracket only supports loads that are normal to its flange surface. It slides when loading is applied in the x-direction.

Local Deflection

Peak Deflection = .0189 in

Von Mises Stress

Exterior view Interior view

Peak Stress = 43 ksi (and is very localized)

Notes:

• A comprehensive analysis of the entire neutral beam port is outside the scope of the current WBS.

• With more effort, the deflections from the global model of the vacuum vessel can be mapped onto the connecting flange on the neutral beam port.

• However, it would be challenging to place an actual neutral beam on the global model as currently constructed since it is split down the middle of the neutral beam port and cyclic symmetry is used to form the 3 period model.

Global model of vacuum vessel structure (all ports capped)

Global model is split at the neutral beam port

Appendix: Very preliminary neutral beam port

analysis with vacuum crush loading

Peak Deflection = 0.0226 in Peak Stress = 44 ksi (essentially unchanged from the case without pressure loading)