mqxfs7a analysis of the results of mechanical measurements v

MQXFS7a: Mechanical measurements SS shell weldingEDMS#2400115M. Deloffre, M. Guinchard, K. Kandemir, S. Mugnier, D. Thuliez

8/23/2021

Evaluate additional stresses induced by the Stainless Steel shell welding on the MQXFS7a structure;

Mechanical measurements need to be done online during welding based on optical fiber instrumentation + electrical instrumentation at every welding step ;

Mechanical instrumentation is compatible for measurement during cool down and powering tests.

Context

MQXFS7a - Shell Welding Mechanical Measurements - EDMS2400115 2

Al Shell instrumentation :

• 3 Sections (Z) instrumented with biaxial strain measurements every 90°. Shell already instrumented will be used;

Coil poles instrumentation :

• One section (Z) instrumented with optical and electrical biaxial strain per coil;

Rods instrumentation :

• 4 rods instrumented for traction stress measurements.

Instrumentation - Baseline


Stainless Steel Shell instrumentation :

• 8 additional spots (inside/outside) instrumented with uniaxial strain measurements at +/- 35 °;

Goal : Evaluate traction and bending azimuthal stresses on the SS shell induced by the welding

Instrumentation – Additional


Azimuthal Strain gauge location

Azimuthal Strain gauge location (hidden side)

Stainless Steel Shell instrumentation :

• 2 lines of 5 measuring spots (outside) instrumented (top shell) with uniaxial strain (longitudinal) measurements at +/- 45 °;

Goal : Evaluate the longitudinal strain distribution along the SS shell structure.

Instrumentation – Additional


Instrumentation – Labelling


Results – Coil pole measurements


-750

-650

-550

-450

-350

-250

-150

-50

Loading Cooldown#1 Warm up#1 Cooldown#2 Warm up#2 Before 1st

welding pass

After 3rd

welding pass

(MIG)

Check on HFM

insert

Cooldown#3

Str

ain

[µ

m/m

]

MQXFS7a - Coils - Azimuthal Strain

CO113T

CO114T

CO207T

CO211T

CO113T_FBG

CO114T_FBG

CO207T_FBG

CO211T_FBG

FEA model - 200 um Gap

AVG Strain T [µm/m]

Results – Coil pole measurements


-1100

-900

-700

-500

-300

-100

100

300

500


welding pass

After 3rd

welding pass

(MIG)

Check on HFM

insert

Cooldown#3

Str

ain

[µ

m/m

]

MQXFS7a - Coils - Longitudinal Strain CO113Z

CO114Z

CO211Z

CO113Z_FBG

CO114Z_FBG

CO207Z_FBG

CO211Z_FBG


AVG Strain Z [µm/m]

Results – Rods


0

50

100

150

200

250

300

350


welding pass

After 3rd

welding pass

(MIG)

Check on HFM

insert

Cooldown#3

Str

ess

[M

Pa

]

MQXFS7a - Rods - Longitudinal Stress

RAZ

RBZ

RCZ

RDZ


AVG Stress Z [MPa]

Results – Stainless Steel Shell – Azimuthal


Strain gauges compensation

Active Strain gauges

Room temperature

4.5 K

50 K

1.9 K

Results – Stainless Steel Shell – Longitudinal


Strain gauges compensation

Active Strain gauges

Room temperature

4.5 K

50 K

1.9 K



-250

-200

-150

-100

-50

0

50

100

Tra

ctio

n S

tre

ss [

MP

a]

MQXFS7a - SS Shell - Connection Side

Before 1st welding pass

After 1st welding pass (TIG)

After 2nd welding pass (MIG)

After 3rd welding pass (MIG)

On the Trailer - SM18 hall

Check on HFM insert

Inside cryostat - Before cooling

Cooldown#3-250

-200

-150

-100

-50

0

50

100

Tra

ctio

n S

tre

ss [

MP

a]

MQXFS7a - SS Shell – Non Connection Side

-80

-60

-40

-20

0

20

40

60

80

Be

nd

ing

Str

ess

[M

Pa

]

MQXFS7a - SS Shell – Non Connection Side



-80

-60

-40

-20

0

20

40

60

80

Be

nd

ing

Str

ess

[M

Pa

]

MQXFS7a - SS Shell - Connection Side






Check on HFM insert


Cooldown#3

Results – Stainless Steel Shell – Longitudinal


CS NCS -1400

-1200

-1000

-800

-600

-400

-200

0

200

Str

ain

[µ

m/m

]

MQXFS7a - 316LN Shell - Longitudinal Strain "Side B"





Check on HFM insert

Cooldown#3

-1400

-1200

-1000

-800

-600

-400

-200

0

200

Str

ain

[µ

m/m

]

MQXFS7a - 316LN Shell - Longitudinal Strain "Side A"






Check on HFM insert


Cooldown#3

Results – Stainless Steel Shell – Powering @6.5kA


• 100% of the mechanical instrumentation (optical and electrical) is working at cold thanks to the SM18 team support to refurbish the optical fiber feedthroughs installed on the test stations;

AFTER WELDING AT RT :

• Coils stress state :

No major modifications, +/- 50 µm/m during transitory thermo-mechanical effects of the complete structure ;

• Rods stress state :

No major modifications ;

• Stainless steel shell :

Between 5 and 47 MPa of traction stresses measured with a strongest effect on the bottom shell ;

No conclusive measurements for the longitudinal directions at this stage, Thermal cycles will be more interesting.

Conclusion


AT COLD TEMPERATURE:

• Coils stress state :

No major modifications comparing to the last cool-down;

• Rods stress state :

No major modifications comparing to the last cool-down;

• Stainless steel shell :

Surprising compressive stresses measured in azimuthal and longitudinal directions ;

No indications to discard data at this stage ;

This effect was already observed during cool-down of MQXFBP1 (positive / negative strains) : https://edms.cern.ch/file/1851752/1/MQXFB_results_2019.xlsx

Conclusion


Results – Coil pole measurements during welding


TIG#01 TIG#01MIG#01MIG#02

MIG#01MIG#02

mqxfs7a analysis of the results of mechanical measurements v

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