Upload
hortense-beverly-hill
View
215
Download
0
Tags:
Embed Size (px)
Citation preview
NSTXNSTX Supported by
NSTX Centerstack Upgrade Project Meeting
P. Titus April 14, 2010
PF4/5 Terminal Stress
Existing PF4/5 Support Weld Algorythm
Moment Influence Coefficients
Bottom “Lid” Torque with Access Holes
PF5 Terminal Analysis16.0 kA in PF4 and 31.8kA in PF5
As of Oct CDR:“We are Still Evaluating the Appropriate Loading Design Basis.
Present Analyses based on Worst Case Currents Provide Conservatisms That Will Be Translated into Cost Savings During the PDR”
For the April 29 Peer Review:
Very few areas are being qualified using maximum power supply loads from the design point.
Qualification is based on Max and Min loads and load combinations for the 96 scenarios from the Design Point
OrMax and min loads, and stresses from an envelope of the Global model results, run for the 96 scenarios.
In addition: All calculations will be required to specify an algorithm for computing critical stresses temperatures etc, for the DCPS to limit.
Currents for Sept 8 Design Point (Exclusive of OH)
-40
-30
-20
-10
0
10
20
1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96
data Number
Ter
min
al C
urr
ent (A
mps)
PF1AU
PF1BU
PF1CU
PF2U
PF3U
PF4
PF5
PF1AL
PF1BL
PF1CL
PF2L
PF3L
Machine Protection System Algorithms
PF1,2,3 supports, welds bolts – At this stage, These are just calculated from influence coefficient matrix loads divided by weld or bolt area. Proposing to add Moment Influence Coefficients
PF 4/5 support weldment (see example)PF4/5 Conductor (Titus)
OH Preload-Launch-TF temperature dependencePF1a-OH interaction StressVertical Loads on pedestal load path (TF Flag Bolts, Pedestal hilti’s), (Ali)
TF Strap (T. Willard) – Mostly designed to TF max Current. DCPS should trip if vertical field exceeds limit (.24T?)
TF OOP loads are a Special Problem
Addition of Moment Influence Coefficients to DCPS
Bolt Loads are calculated from the vertical force and the moment divided by the width of the bolt pattern
Bolt Loads are calculated only from the vertical force.
Moment influence Coefficients are calculated about a geometric center of the coil.
Comparison with Ron’s Influence Coefficients
This PF3 support analysis only Included the vertical load on PF3. Moments will add to bolt and weld stress. It is proposed to have the DCPS calculate bolt and weld stresses with the moment applied.
AISC Table 1.17.5 Minimum weld sizes recommended for joined plate sizes.
HM quoted this in his LTX analysis – Why we were concerned with only 1/8 inch structural welds
The torsional moment for design of the lid/flex/diaphragm bolting and the TF steps or keys is 0.3MN-m for the lower lid – Without Holes
PF4U PF5U PF4L PF5L
From FEA 996520 803729 4000 1500
Weld Pa/Newton 996.52 803.729 4 1.5
Weld psi/lb 0.964377 0.814102 0.004052 0.00151936
PF4/5 WeldmentNominal Weld = 5/16 in. QA Effective Weld = 1/4FEA Weld Model Thick =10mm Weld Stress to FEA Stress = (.01*39.37)/.25 = 1.57
Weld Allowables are: 14 Ksi for Visual Inspection 20 ksi for Penetrant Inspection
PF4/5 Support Weldment Strss Algorythm
PF4/5 WeldmentNominal Weld = 5/16 in. QA Effective Weld = 1/4FEA Weld Model Thick =10mm Weld Stress to FEA Stress = (.01*39.37)/.25 = 1.57
~25MPa * 1.57 = 39.25MPa = 5629 psi
Based on the Corner Peak:58 MPa*1.57 = 13274 psi
14 ksi is allowed with only visual inspection
Weique Que told me that the protection system would only allow 18 kA based on my multipliers.
I improved the mesh around the corner –Still has a sharp point, but the stresses are lower.
For 30.8kA this is (31.8/20)^2*(~70) = 176 MPa. Satisfies Copper metal Allowable of 233
Low Modulus Insulation Coil Results (Expect Mylar Slip Plane)
Is cyclic slippage OK for the Mylar?I would use 12 supports
The torsional moment for design of the lid/flex/diaphragm bolting and the TF steps or keys is 0.28MN-m for the lower lid – With Holes -Only slightly less than without.