# Presentation: 373030

## NSTX TF Flag JointDesign ReviewINTRODUCTIONC Neumeyer8/7/3

## BACKGROUND

- TF joint failed on February 14, 2003 due to structural weaknesses
- At the April 10, 2003 review.....
- cause of failure was explained
- new design was presented
- sufficient confidence was gained to proceed with conductor machining
- Since April the analysis, testing, and design has been completed
-  chits generated during the April review have been resolved
- Purpose of this review is to examine the final design
- identify any shortcomings which may need correction
- Additional review in September will assess cost and schedule
- today’s review will establish that the technical basis is sound

## PURPOSE OF REVIEW

- Obtain critique of new design of the TF Flag Joint
- Identify any shortcomings needing further attention (chits)
- Confirm viability of Flag Joint Design for 6kG operation

## SCOPE OF REVIEW

- TF Flag Joint and Integrated Assembly
- Inner Leg / Flag Interface *(the joint)*
- Flag
- Flag Fasteners *(threaded inserts, studs, washers, nuts, etc.)*
- Flag Structural Supports *(Boxes, Shear Shoes)*
- Hub Assembly/Torque Collar
- Built-in Instrumentation Features
*Other aspects may be discussed but are out of scope*

## AGENDA

## REVIEW PROCEDURES

-  Chits to be submitted to Chairman B Nelson
-  Chits to be dispositioned by Review Board
-  Chits to be resolved  by Cog Engr C Neumeyer

- P. Anderson, GA
- L. Dudek
- J. Irby, MIT
- B. Nelson,ORNL**

- **  Chair
- *    Ex-officio
-   Remote participant

- C. Neumeyer*
- P.  Peterson, GA
- P. Titus, MIT

-  G. Voss, Culham

## RECOVERY ACTIVITIES

## DESIGN

- 3D modeling complete, including...
-  integrated TF inner leg bundle
-  coolant tube routing and bulkhead
-  outer leg connections
- Fabrication drawings complete, including...
-  conductors
-  flags
-  flag boxes
-  shear shoes
-  hub assembly
-  torque collar

## ANALYSIS

- Structural FEA complete, including...
-  both tiers of conductors
-  out-of-plane load path through spline
-  collar and wet lay-up representation
-  in-plane, out-of-plane, thermal loads
-  SOFT, EOFT, EOP cases
- Other analysis complete, including...
-  force calculations
-  temperatures, including joint temperature rise
-  fastener sizing calculations
-  miscellaneous calculations
*Formal documentation and checking *
*is presently underway*

## TESTING

- Component testing (design input data) consists of:
*Pull-out tests on threaded inserts *
*- one time and 50,000 cycle at 100**o**C*
*Pull-out tests on bolts threaded in copper *
*- one time and 50,000 cycle*
*Friction coefficient and electrical resistance tests*
*Shear tests on torque collar attachment*
*Status: Complete*
- Prototype testing (design verification) consists of:
*Mechanical mock-up tested for 50,000 cycles*
*Electrical mock-up tested at full current and** I**2**T*
*Status: In Preparation*

## HIGHLIGHTS SINCE APRIL

- Structural FEA completion
- greater insight into thermal-induced behavior
- Shear Shoe (a.k.a. Shear Key) re-design
- Torque Collar
- - Three segment collar
- - Torsion-only design (de-coupled vertical and radial loads)
-  Improved epoxy wet lay-up
- Voltage probe using commercial spring-loaded probe
- Precision measurement of contact resistivity vs. pressure
- Component tests completed