1. Component Testing Test Setup TapLok Insert Shear Key Copper Threads
NSTX TF FLAG JOINT REVIEW 8/7/03
Test Setup
TapLok Insert
Shear Key Copper Threads
Friction Tests
Collar Shear Tests
Michael Kalish

2. Test Setup MTS Hydraulic Test Stand
Plots Load vs Deflection up to 100,000 lbf
Provides cyclic Testing Capabilities

3. Flag Stud TapLok Inserts

4. TapLok Pull Tests
Objective: To determine pull out strength as well as to prove durability of insert at 50,000 cycles
TapLok Inserts installed in spare lengths of conductor
Test samples prepared in a manner identical to final conductor configuration

5. TapLok Static Pull Tests
Static tests were performed on KeenSerts and both .687” and .562” long TapLok inserts
Total of 13 TapLok inserts & 8 KeenSerts
Medium length .562” long TapLoks inserts chosen for design
Results presented here are for only the .562” long insert

6. TapLok Pull Tests
Specimen in Test Fixture

7. Static Pull Test Plot
A graph of force vs deflection is generated for each sample
Displacement vs Force Curve for Tap Lok #4, 3rd Sample
Peak Force = 12,500 lb

8. TapLok Static Pull Test Results
Un-Cycled Sample
Break Force
TLC-1
14500
TLC-2
12500
TLC-3
TLC-4
11500
TLC-5
Average =
12700
Average pullout force for .562” TapLok was 12,700 lbf corresponding to a calculated ultimate shear stress of 29.9 KPSI
This value derived from the test data is 36% higher than the assumed ultimate strength in the fatigue analysis and twice the design load

9. Cyclic Testing, TapLok
Using same test setup medium length (.562”)Tap Lok inserts were cycled then pulled
Test sample was heated to 100 C during cycling
Six test pieces were cycled at 5,000 to 6,000 lbf for 50,000 cycles or greater
Test levels reflect the 1,000 cycle thermal loading case
Cycled with 1 Hz Sine Wave
Two samples were cycled at 5,000 to 7,360 lbf to test at the 2x Stress at design life condition
After cycling static pull tests determined if pull out strength had degraded

10. Results Cyclic Pull Tests for TapLok
No Failure of any sample including two samples cycled at 2x Stress and 50,000 cycles (5,000 lbf to 7,360 lbf)
Pull out strength relatively unchanged for samples cycled at design loads
Yield strength values averaged 82% of Tensile strength
Samples cycled at temperature did not vary from unheated samples

11. Component Testing Test Setup TapLok Insert Shear Key Copper Threads
NSTX TF FLAG JOINT REVIEW 8/7/03
Test Setup
TapLok Insert
Shear Key Copper Threads
Friction Tests
Collar Shear Tests
Michael Kalish

12. Shear Key Copper Threads

13. Shear Key Copper Threads, Static and Cyclic Testing, Test Setup

14. Shear Key Copper Threads, Static and Cyclic Testing
Objective: To verify the strength of the threaded holes in the conductor for the shear key hardware under both static and fatigue conditions
Test samples using conductor copper were prepared with the same hole / thread specifications as the actual conductor
A subset of samples were oven cycled before testing
Cyclic testing of copper threads was performed at room temperature at 5,000 lbf to 6,000 lbf for 50,000 cycles

15. Shear Key Copper Threads, Static Results

16. Shear Key Copper Threads, Static Results (cont.)
Correlation between pull out force and the number of threads pulled explains scatter
By design shear key bolt will catch 8-9 threads
A-1 12,500lbs peak, 8 Threads
A-2 12,620lbs peak, 8.5 Threads
A-3 13,120lbs peak, 9 Threads
A-4 12,500lbs peak, 8 Threads
A-5 10,880lbs peak, 7 Threads
A-6 12,380lbs peak, 8 Threads

17. Shear Key Copper Threads, Cyclic Results
No appreciable degradation in the pull out strength of samples subjected to 50,000 cycles
One sample subjected to 233,000 cycles with same result

18. Shear Key Copper Threads, Cyclic Results
Yield Strength for both cycled and uncycled samples averaged 82% of the pullout strength
Tests were performed on copper samples subjected to oven thermal cycling with no noticeable degradation to pull out strength
Average pullout force for static test of threads was 12,780 lbf corresponding to a calculated ultimate shear stress of 29.0 KPSI
The value derived from the test data is 36% higher than the assumed ultimate strength in the fatigue analysis and 2x the design load
All samples survived cyclical testing

19. Friction Test
Objective: To characterize the COF for the flag electrical faces under varying compressive loads.
Two horizontal load cells measure compressive force provided by eight 3/8th inch bolts
Specimens are machined and plated after each run
Vertical load is applied to offset middle block and force / displacement is recorded

20. Friction Tests Results, Plot
Plot of Force vs Distance
Force is recorded at point where nonlinear behavior begins

21. Friction Test Results (cont.)
Mean COF = .41
Min. Value = .39
Results consistent for varying compressive loads

22. Component Testing Test Setup TapLok Insert Shear Key Copper Threads
NSTX TF FLAG JOINT REVIEW 8/7/03
Test Setup
TapLok Insert
Shear Key Copper Threads
Friction Tests
Collar Shear Tests
Michael Kalish

23. Collar Shear Test Objectives:
To test the shear strength of the Torque Collar both statically and after fatigue testing
To correlate shear strength and clamping pressure
To test for fatigue endurance at 50,000 cycles

24. Collar Test Sample Evolution
Total of five sample groups tested
Initial collar test of first three groups consistently failed at the epoxy to steel interface
Improvements made in groups 4 and 5 resulted in 22% increase in average shear stress test results
Grooves added to plates to improve adhesion
New higher adhesion epoxy used
Only groups 4 and 5 which represent the final configuration are reported on here

25. Collar Sample Test Setup
Test Fixture Designed to provide compression as sample is tested in shear or cycled
Dual Load Cells measure compressive load and the MTS load cell measures shear load

26. Plot of Shear Collar Static Sample Tests
Clamping pressure vs shear failure loads show good correlation

27. Test Samples, Static Tests
Adhesive interface to steel plates is no longer the failure mode after addition of slots and improved epoxy

28. Cyclic Collar Sample Testing Results
Initial sample was cycled at 1,800 psi with a high cycling rate of 1 Hz and a low clamping load of 226psi. This sample failed prematurely at 2,800 cycles.
Six subsequent samples lasted for 50,000 cycles or greater with no failure using lower cycling rates and higher clamping loads
One sample under went 233,000 cycles at 1,300 psi and low clamping load with no failure.
Another sample was cycled at 1,600 psi for 123,600 cycles without failure (1,000psi clamping)
Group
Sample #
Clamp (psi)
Number of Cycles
Fatigue Stress Applied (psi) G4 6
226
2800
1832 1
373
233000
1304 G5 3
243
63079
1311 6B
999
123600
1589 2B
1847
51420
1766 5A
618
50243 5B
965
51250
1793

29. Plot of Shear Collar Cyclic + Static Sample Tests
Blue data points are un-cycled test specimens
Pink data points represent samples broken after cycling