Vacuum Vessel lateral loading (Neutral beam port only)

1
Vacuum Vessel lateral loading (Neutral beam port
only)

• 5-12-05

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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 p122/4 1696 lb) applied on
  the neutral beam port lateral support.

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Model
Refined mesh near lateral support bracket
Only Neutral beam is modeled
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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.

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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.

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Local Deflection
Peak Deflection .0189 in
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Von Mises Stress
Exterior view
Interior view
Peak Stress 43 ksi (and is very localized)
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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
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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)