Overview of MCWF Interfaces

The interface configuration is nearing finalization.

5 welds/period (typ.) in central region.

1 of 3 identical field periods

C-C inner legs are electrically insulated & left to slide ( motion ~0.5 mm).

Alumina Coated SS Shim Friction

Characteristics

y = 0.0005x + 0.6733

R2 = 0.0006

y = 0.0169x + 0.3948

R2 = 0.2093

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 2 4 6 8 10 12 14 16 18 20

Contact pressure (ksi)

Ap

pa

ren

t m

u With Binder

No Binder

Linear (With Binder)

Linear (No Binder)

Mu needed on inner legs to prevent inner leg slip is too high

Coefficent of Friction Needed to Prevent IL SlipCombined Coil Model (Mod/TF/PF)

Inboard Regions With and Without Added Bolts - Dead Load+EM+CD

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

cc2i

nt

cc2i

nb

bc2i

nt

bc2i

nb

ab2i

nt

ab2i

nb

aain

t

aain

b

abin

t

abin

b

bcin

t

bcin

b

ccin

t

ccin

b

Joint-Location

mu

These IL’s will be welded to address high mu requirement.

Mu with 2/3 criteria factor applied

Mu based on data

C-C will be insulated and left to slide

With No Slip on inner legs, friction required on the outer legs to prevent them slipping is well within the friction capabilities of the alumina coated shims with excellent

factors of safety.

Coefficent of Friction Needed to Prevent SlipCombined Coil Model (Mod/TF/PF)

Outboard Regions Dead Load+EM+CD

0.000

0.050

0.100

0.150

0.200

cc2b

cc2t

bc2b

l

bc2b

rl

bc2b

ru

bc2t

rl

bc2t

ru

bc2t

l

ab2b

l

ab2b

r

ab2t

rl

ab2t

ru

ab2t

l

aabl

aabr

aatr

aatl

abbl

abbr

l

abbr

u

abtr

abtl

bcbl

bcbr

l

bcbr

u

bctr

l

bctr

u

bctl

ccb

cct

Joint-Location

mu

Highest is ~0.16 vs. measured value of >0.6

Friction = 0.04 on Inner-leg region, mu = 0.4 everywhere else

No Inboard Bolt Friction

Frictionless In board leg

Peak Shear is 4.8 Kips

Sliding is 19 mils

0.00220.00440.00660.00880.01100.01330.01550.01770.0199

InchesBolt 32

Bolt 1

C-C Bolt Preload & EM-Driven Bolt Shear Load with no in board bolts or friction with perfect fitup

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Bolt #

Te

ns

ion

, k-l

b

0

2

4

6

Sh

ea

r L

oa

d, k

ip

Tension no pucks (Pre), kip

Shear with mu = .4 everywhere (Pre+EM-Pre), Kip

Shear with mu = .04 on unbolted regions (Pre+EM-Pre), kip

Definition of shim segments

cc2t

cc2b

cct

cc2int

ccb

ccint

bc2tlbc2tru

bc2trl

bc2bru

bc2int

bc2brlbc2bl

bcint

bctlbctru

bctrl

bctrl

bcbrlbcbl

aaint

aatl

aabl

aatr

aabr

ab2int

ab2tl ab2tru

ab2trl

ab2br

ab2bl

abint

abtl

abtr

abbru

abbrlabbl

-60 deg

+60 deg

0 deg

cc2inbbc2inb

ab2inb aainb

ccinbbcinb

abinb

Our plan: weld the inner legs of all but C-C

A-A

• Configuration: weld all intra-period interfaces and maintain a bolted / insulated interface between the field periods.

•This addresses the inter-period friction & deflection requirements and bolt stress very nicely.

• This is also very compatible with machine assembly procedures.

C-C Slide Concept

• Slide plates located top & bottom and along mid-section.

• Plate thicknesses determined by metrology measurements.

• Slide plates will be restrained to react friction loads with adequate F.S.

• 3 additional bolts & friction shims will be added top and bottom to address bolt loading issue.

Bolts can be added on the C-C interface if necessary

Can also access bolts from the side