NSTX Supported by NSTX Centerstack Upgrade Project Meeting P. Titus March F

PF1CL TF Shear Influence Coefficient Calculation

Upper Middle Lower

F Copper Adhesive/Insulation System Nominal specimen dimensions: Thickness: in. (actual thickness typically varies from to 0.125) Width: 0.25 in. Length: 1.1 in. Copper thickness: in. Copper surface preparation: Solvent cleaned/degreased, grit blasted (both sides), CTD-450 primer applied (both sides) Composite construction: Typically 7 plies of 6781 S2 glass fabric on either side of copper, resulting in a nominal 0.56 fiber volume fraction. If 6 plies are used per side, volume fraction is reduced to Span Ratio (lower support span to thickness) is typically set to 5.0. However, the span can be adjusted to reflect a ratio of 3 to 8. If a span longer than 6 is needed, the overall length of the specimen would need to increase.

Shear Stress in the Copper and insulation interface is about 800 psi or 5 MPa inch Half Span Quarter Symmetry Model with 5 lbs – Represents 20 lbs on the full sample Von Mises Stress Vertical Displacement

Shear Stress in the Copper and insulation interface is about 800 psi or 5 MPa inch Half Span Quarter Symmetry Model with 5 lbs – Represents 20 lbs on the full sample Von Mises Stress Vertical Displacement

PF5 Upper Coil DCPS Input Pick a Coil (PF5 Upper) Pick a Worst Place (At the New Columns)

Forces on PF5 (and 4) due to Unit Terminal Currents (actually 1000A) in PF 4 and 5 15 Other Sets of Loads Are Calculated, Including one for the Plasma

Calculated Influence Coefficients With the PF5 Self Coefficient Subtracted Out Calculated Influence Coefficient, Load #14 – Stress Due to PF14 Lower

kA OH Scenarios kA OH Scenarios

Check Influence Coefficients Against Global Model

Full Current in PF4 and 5, 16 and 32 kA, Produces 50 Mpa Conductor Stress With No Thermal

Full Current in PF4 and 5, 16 and 32 kA, Produces 21 Mpa Smeared Stress from the influence coefficients Multiply Influence Coefficient Results by 37/21 to get conductor stress?

A Bit of History A Mechanical Shear Connection with Studs was Suggested Vessel Knuckle Clevis

Welded Clevis Replacement

This Detail needs to be radiused

Weld mesh is poor – use hand calcs and the shear stress distribution on the back of the lug Looks like the vertical welds don’t contribute as much – But may be a mesh effect

Weld Needed to Take 20,000 Shear Load