FINITE ELEMENT ANALYSIS OF NSTX FLAG JOINT
DESIGN
Irving J. Zatz
August 7, 2003
FEATURES OF FEA MODEL• INCLUDES ALL ESSENTIAL STRUCTURAL
COMPONENTS CONTRIBUTING TO FLAG JOINT PERFORMANCE– FLAGS - BOXES– COLLAR - HUBS– CENTER STACK - BOLTS– SPLINES - UMBRELLA– etc.
FEATURES OF FEA MODEL
• NON-LINEAR VARIABLE CONTACT ALONG FACE OF JOINT– CONTACT PRESSURE CAN BE
ACCURATELY MONITORED– ANY LOSS OF JOINT CONTACT CAN BE
DETECTED– FRICTION COEFFICIENT CAN BE
SPECIFIED
FEATURES OF FEA MODEL
• SHEAR KEY & PRE-LOADED BOLTS– CAN ACCURATELY DETERMINE AXIAL
AND/OR SHEAR LOAD TRANSFER TO COPPER AND INSERTS
LOAD CASES EXAMINED
• START OF FLAT TOP (SOFT)
• END OF FLAT TOP (EOFT)
• END OF PULSE (EOP)
ANALYTICAL ASSUMPTIONS
• STATIC ANALYSIS - DOES NOT ACCOUNT FOR FATIGUE AND CREEP EFFECTS
• TOLERANCES ARE PERFECT (e.g., FLAG-TO-TURN FLATNESS)
• FIT-UPS ARE PERFECT (e.g., FLAG-TO-BOX POTTING)
LOAD CASE (35)
• BOLT PRE-LOAD 5000 LBS/BOLT
• 6 kG EM LOADS-(with FLEX EFFECT)
• EOFT TEMPERATURES
• 0.4 FRICTION ASSUMED
LOAD CASE (35C)
• BOLT PRE-LOAD 5000 LBS/BOLT
• 6 kG EM LOADS-(with FLEX EFFECT)
• EOFT TEMPERATURES
• 0.2 FRICTION ASSUMED
LOAD CASE (34C)
• BOLT PRE-LOAD 5000 LBS/BOLT
• 6 kG EM LOADS-(with FLEX EFFECT)
• EOFT TEMPERATURES
• NO FRICTION ASSUMED
LOAD CASE (35B)
• BOLT PRE-LOAD 5000 LBS/BOLT
• 6 kG EM LOADS-(with FLEX EFFECT)
• SOFT TEMPERATURES
• 0.4 FRICTION ASSUMED
LOAD CASE (35D)
• BOLT PRE-LOAD 3000 LBS/BOLT
• 6 kG EM LOADS-(with FLEX EFFECT)
• SOFT TEMPERATURES
• 0.4 FRICTION ASSUMED
LOAD CASE (35E)
• BOLT PRE-LOAD 5000 LBS/BOLT
• NO EM LOADS
• END-OF-PULSE TEMPERATURES
• 0.4 FRICTION ASSUMED
SUMMARY OF RESULTS
