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.