NSTXNSTX Supported by
NSTX Centerstack Upgrade Project Meeting
P. Titus March 30 2011
Insulation Short Beam Tests – Failure Modes
Ripple Loads on PFPF4/5 Existing Support Analysis
Top flag Von Mises Top flag hoop stress
315 MPa (45.7 ksi) 257 MPa (37.3 ksi)73.7 MPa (10.7 ksi)
Han Zhang Current Diffusion/Thermal/Stress Model
We Expect De-Lamination
We Expect De-Lamination
Figure 33 - Bonded tape delaminated from copper turn
Figure 34 - Sleeve of bonded glass fiber tape where copper turn slid out
TFTR D&D PROJECTFINAL EXAMINATION AND TESTING
OF THE TFTR TF-COILSDecember 18, 2002
Irving J. Zatz
•Broke at only 100 lbs•Broke at Kapton Bonds•Withstood 21kV after air gap tracking fixed.
U.S. ITER Large-Scale Compression-Fatigue Tests of CS Coil Insulation 27 June 2008
Stresses Due to OH2 Reverse Current Fault, Alcator C-Mod Belleville
Preload is Applied as Nodal Forces on the Top of the model
Analysis Predicted De-Bonding but Not Failure
Inspection Showed Crazing Here
No Operational Problems have been Experienced
Conclusion:
Some De-Lamination is Expected
Parting Planes must be predictable and not Cause Tearing of Fiberglass Insulator
OH Kapton Interleaved Insulation Will Part Reliably – Like Old ITER Design
Recent Measured Results for the CTD 425 System Show Preferential Failures at Copper Bond Surface, But Sufficient Shear Strength to Support TF Torsional Loads
WithPlasmaNo Plasma
Without Existing Support Strut
With Existing Support Strut
180 Mpa or 26ksi is Marginal for Static Weld AllowablePresent 96 Scenarios produce ~22 ksi (next Slide)Won’t Pass Fatigue.
Results from Influence Coefficient Multiplication for Sx in RSYS 5 (cylindrical).
With No Column This Stress Can be Considered from PF5 Loads Only
+13kA/- 24 kA Scenario from Latest ( as of March 2011)Design Point Spreadsheet
Present Column Doesn’t Do Much and Doesn’t Compare Well with the Added 3.5 inch Column
Could we Replace it?
TF Ripple Loads – Figure Created by Subtracting the PF+TF Load File from the PF Only File, Then Plotting Only PF Loads
TF Ripple Loads on PF 4 and 5 Upper
Plotted with TF leg Segments to Show Torque Loading Near the TF Legs
TF Ripple Loads on PF Coils are Included in Willard’s, Han’s, Andrei’s and Titus’ Loads – But not Influence Coefficient Calculations.
