2D ANSYS analysis of the QXF structure

Mariusz Juchno

QXF internal meeting19 February, 2013

Keypole material and size

• Keypole slot added

19/02/2013Mariusz Juchno 2

L

W/2 D

• I0 = -19670 A• Keypole

– D = 4.64 mm (from HQ drawing)– L = 10 mm– W = 6, 10,15 mm (8 mm hole needed)

• Shellth = 27 mm• Interf = 650 um• Pbladder = 41.7 MPa (for interf + ~100 um)• Special cases to illustrate possible adjustment

– (*) Interf = 600 um -> Pbladder = 38.9 MPa– (**) Interf = 625 um -> Pbladder = 40.4 MPa

Parameters (155 T/m, 90% of Iss)

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Keypole study summary

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Mat W Coil σeq max

warmCoil σeq max cold

Iron σeq max warm

Iron σI max cold

Coil pcont

Al 6 mm 101 164 208 233 -4.5, -12.4

10 mm 102 164 199 234 -4.3, -12.6

15 mm 104 165 190 234 -4.0, -12.8

G10 10 mm 106 167 195 233 -8.1, -14.7

15 mm 109 168 190 232 -9.3, -15.7

SS 10 mm 100 162 202 234 -2.4, -11.1

15 mm 100 162 190 235 -1.1, -10.7

Ti 10 mm 101 161 201 235 -1.2, -9.6

15 mm 102 160 190 235 0.7, -8.8

G10 * 10 mm 99 164 185 223 -3.6, -11.8

G10 ** 15 mm 106 167 183 228 -7.0, -14.1

• Keypole width variation – effect only visible in case of iron σeq max at warm

• Thermal contraction and elastic modulus plays important role for coil contact pressure (preload)

• Best candidates:– G10

• Simplifies insulation scheme• Bigger thermal contraction -> intercepts less force• Might allow to reduce preload• Risk of loosing contact with collars

– Titanium• Can be integrated in the pole• Smaller thermal contraction -> intercepts more force• Requires more preload

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Keypole study summary

Sensitivity study

Mariusz Juchno

QXF internal meeting19 February, 2013

Interference

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Interference

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-50 0 50180

190

200

210

220

230

240

250

interference [m]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-50 0 50-16

-14

-12

-10

-8

-6

-4

-2

0

interference [m]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

-50 0 5038

39

40

41

42

43

44

45

interference [m]

p [M

Pa]

Bladder pressure

bladder pressure

-50 0 5090

100

110

120

130

140

150

160

170

180

interference [m]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

• Pbladder adjusted to always have +100um more than interference

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Shell thickness

Shell thickness

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-2 -1 0 1 2180

190

200

210

220

230

240

250

shellth [mm]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-2 -1 0 1 2-16

-14

-12

-10

-8

-6

-4

-2

0

2

shellth [mm]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

-2 -1 0 1 239

40

41

42

43

44

45

shellth [mm]

p [M

Pa]

Bladder pressure

bladder pressure

-2 -1 0 1 290

100

110

120

130

140

150

160

170

180

shellth [mm]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

• Iron σI stress at cold slightly more sensitive than in interference case

• OD is fixed• Pbladder adjusted to have

fixed interference

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Pad thickness

Pad thickness

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-10 -5 0 5 10180

200

220

240

260

280

300

320

padth [mm]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-10 -5 0 5 10-15

-10

-5

0

5

padth [mm]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

Yoke(busbar slot)

Pad(corner)

• Gain (when decreasing padth):– Reduction of iron σI stress at cold– Improve the contact (L1 more than L2)– Should improve keypole contact

• Loss (when decreasing padth):– Increase of stress in the coil– Increase of stress in the iron at warm

(pad cornet – might not be important)

-10 -5 0 5 1080

100

120

140

160

180

200

padth [mm]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

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Vertical key position

Vertical key position

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-20 -15 -10 -5 0-14

-12

-10

-8

-6

-4

-2

0

2

keyy [mm]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

• Gain (when shifting the key down):– Reduction of coil stress at cold– Reduction of the pole contact offset between

layers– More space for the bladder

• Loss (when shifting the key down):– Increase of σI stress in the iron at

cold (mostly busbar slot)– Chance for losing keypole contact

-20 -15 -10 -5 0160

180

200

220

240

260

280

300

keyy [mm]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-20 -15 -10 -5 0100

120

140

160

180

200

220

keyy [mm]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

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Key length

Key length

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0 5 10 15 20-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

keyh [mm]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

• Gain (when lowering the bottom face):– Reduction of coil stress at cold– Reduction of the pole contact offset between

layers– Smaller chance for losing keypole contact

• Loss (when lowering the bottom face):– Increase of σI stress in the iron at

cold (mostly busbar slot)

0 5 10 15 20140

160

180

200

220

240

260

keyh [mm]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

0 5 10 15 20100

110

120

130

140

150

160

170

180

190

keyh [mm]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

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Pad Engagement (?)

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Pad Engagement (?)

-10 -5 0 5 10100

110

120

130

140

150

160

170

180

eng [mm]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

-10 -5 0 5 10180

200

220

240

260

280

300

320

eng [mm]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-10 -5 0 5 10-14

-12

-10

-8

-6

-4

-2

eng [mm]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

• Gain (decreasing eng):– Control over the pole contact

pressure (not significant)– Space for axial rods

• Loss (decreasing eng):– Plasticization of the pad

corner (artifact?)

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Busbar slot angle

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Busbar slot angle

-6 -4 -2 0 2100

110

120

130

140

150

160

170

180

busdeg [deg]

[

MP

a]

Maximum stress in the coil

warm - bladder

cold - cooldown

cold - max gradient

-6 -4 -2 0 2180

200

220

240

260

280

300

busdeg [deg]

[

MP

a]

Maximum stress in the iron

eqv

warm - bladder

eqv

warm - preload

I cold - max gradient

-6 -4 -2 0 2-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

busdeg [deg]

p cont

[M

Pa]

Pole contact pressure

layer 1 - mid node

layer 2 - mid node

• Gain (when increasing):– Small reduction of σI

stress in the iron at cold

Design CriteriaWork in progress

11/15/20122nd Joint HiLumi LHC - LARP Annual

Meeting - H. Felice 21

• Pole-coil contact at 155 T/m (90% of Is),

pcont ≥ 2 MPa in midpoint

• Max bladder pressure < 50 MPa (better 40 MPa?)

• Bladder should open the interf=interfnom + 100μm

• σeq coil max ≤ 150-200 MPa at 4.3K and 155 T/m

≤ 100 MPa at 293K

• All components σ ≤ Rp 0.2

• For iron at 4.3K (brittle) σI ≤ ~200 MPa

Material Rp 0.2 [MPa]

293 K 4.3 K

Al 7075 480 690

SS 316 LN 350 1050

NITRONIC 40 353 1240

MAGNETIL 180 723

Ti 6Al 4V 827 1654

Parameters tuning

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Parameter Reference Modified

Material Al Ti G10 G10

Kpw 15 mm 15 mm 15 mm 12 mm

Interf 650 um +0 +0 +0

Shellth 27 mm -2 -1 -2

Padth 42 mm -4 -2 -2

Keyy 27 mm -2 -1 -1

Keyh 12.7 mm +4 +2 +2

Eng 33 mm -6 -5 0

Busdeg 30o +2 +2 +2

Structure state (90%(1), and 80%(2) Iss)

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Reference ModifiedAl Ti G10 G10

15 mm 15 mm 15 mm 12 mm

Coil σeqv (b) 104 107 110 105

σeqv (k) 71 75 77 75

σeqv (c) 172 174 184 180

σeqv (g) 165 148(1), 131(2) 163(1), 146(2) 160(1), 144(2)

Iron σeqv (b) 190 174 180 175

σeqv (k) 196 170 180 175

σI (c) 219 180 192 186

σI (g) 234 194(1), 192(2) 208(1), 205(2) 199(1), 197(2)

pblad (gap) (3) 42 (750,767um) 40 (740,760um) 40 (733,753um) 39 (730,750um)

Pcont -4, -12 -2, -5(1)

-24, -17(2)

-11, -14(1)

-33, -27(2)

-7, -11(1)

-28, -24(2)

Kp gap 0 um 0 um ~0 um 0 um(3) Pblad conservative due to model symmetry, otherwise around 10% lower -> lower coil and iron stresses during bladder operation

Straight vs Round Collars

Mariusz Juchno

QXF internal meeting19 February, 2013

Geometry

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Coil contact

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• Trapezoid collars– Possible to obtains

similar contact on the midnode

• Round collars– Layer 2 not evenly loaded

while layer 1 overloaded– Tension-compression

transition close to the midnode

-0.8 MPa

-7.7 MPa

-11MPa

-7 MPa

Collar contact

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• Trapezoid collars– More uniform contact

distribution over the length similar to coils height

• Round collars– Force transfer close to

the midplane -> layer 2 gets not enough preload

Structure state

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Reference RoundAl Al

15 mm 15 mm

Coil σeqv (b) 104 107

σeqv (k) 71 86

σeqv (c) 172 200

σeqv (g) 165 137

Iron σeqv (b) 190 190

σeqv (k) 196 191

σI (c) 219 214

σI (g) 234 231

pblad (gap) (3) 42 (750,767um) 42 (752,764um)

Pcont -4, -12 -14, -4

Kp gap 0 um 8 um

• Overloaded 1st layer (200 MPa in the coil after cooldown, and much higher contact pressure)

• 2nd layer not sufficiently loaded – keypole gap opened

• Round collars seem les sensitive to optimization due to force transfer close to the midplane