Component Testing Test Setup Tap Lok Insert Shear

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

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

Flag Stud Tap. Lok Inserts

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

Tap. Lok Static Pull Tests • Static tests were performed on Keen. Serts and both. 687” and. 562” long Tap. Lok inserts • Total of 13 Tap. Lok inserts & 8 Keen. Serts • Medium length. 562” long Tap. Loks inserts chosen for design • Results presented here are for only the. 562” long insert

Tap. Lok Pull Tests • Specimen in Test Fixture

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

Tap. Lok Static Pull Test Results Un-Cycled Sample Break Force TLC-1 14500 TLC-2 12500 TLC-3 12500 TLC-4 11500 TLC-5 12500 Average = 12700 • Average pullout force for. 562” Tap. Lok 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

Cyclic Testing, Tap. Lok • 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 2 x Stress at design life condition • After cycling static pull tests determined if pull out strength had degraded

Results Cyclic Pull Tests for Tap. Lok • • No Failure of any sample including two samples cycled at 2 x 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

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

Shear Key Copper Threads

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

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

Shear Key Copper Threads, Static Results

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, 500 lbs peak, 8 Threads A-2 12, 620 lbs peak, 8. 5 Threads A-3 13, 120 lbs peak, 9 Threads A-4 12, 500 lbs peak, 8 Threads A-5 10, 880 lbs peak, 7 Threads A-6 12, 380 lbs peak, 8 Threads

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

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 2 x the design load • All samples survived cyclical testing

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 3/8 th inch bolts • Specimens are machined and plated after each run • Vertical load is applied to offset middle block and force / displacement is recorded

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

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

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

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

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

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

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

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

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 226 psi. 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, 000 psi clamping) Clamp (psi) Number of Cycles Fatigue Stress Applied (psi) Group Sample # G 4 6 226 2800 1832 G 4 1 373 233000 1304 G 5 3 243 63079 1311 G 5 6 B 999 123600 1589 G 5 2 B 1847 51420 1766 G 5 5 A 618 50243 1766 G 5 5 B 965 51250 1793

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