Apr 21, 2023 S.Movchan Straw manufacturing and QC 1

Test results of straw rejection for 3 criteria

- Dubna 806 straws: Load max F vs elongation dL data shape - test results of straw rejection for 3 criteria - conclusion

Presented by S.Movchan

Apr 21, 2023 S.Movchan Straw manufacturing and QC 2

Dubna 806 straws

data taken from file “Straw_data_05_05.xls”

Apr 21, 2023 S.Movchan Straw manufacturing and QC 3

Cut: F=3.7 kG

dL(mm)

F (kG)

NDubna 806 straws

dL=1 mm

Load max F vs elongation dL: 3-D presentation

Apr 21, 2023 S.Movchan Straw manufacturing and QC 4

Load max F vs elongation dL: 3-D presentation

dL(mm) dL(mm)

F (kG)

F (kG)

N

Good

Bad

3.7 kG

Apr 21, 2023 S.Movchan Straw manufacturing and QC 5

7 straws

8 straws

F=(3.7-8) kG dL=(0-1) mm

dL(mm)

dL(mm)F (kG)

F (kG)

N

N

Zoom of BAD region

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Load max F vs elongation dL

Breaking force vs elongation (Corrected value)

y = 3,18x0,25

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

0,00 2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00 18,00

Elongation, mm

Bre

akin

g fo

rce,

kg

Blue – start strawRed – end straw

data shape

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Dubna data shape is not like expected:

Due to this we have some probability to install “BAD” straw (elongation less than 1 mm) in the Module-0 after straw rejection (non elastic mylar deformation is started after dL=0.5 mm at 100 MPa)

6 samples from Sefar September

Apr 21, 2023 S.Movchan Straw manufacturing and QC 8

Dubna 806 straws

Test results of straw rejection for 3 criteria:- Load max F< 3.7 kG (Strength=100 MPa)

- dL < 1 mm- dL < 1 mm @ Load max F< 3.7 kG

Apr 21, 2023 S.Movchan Straw manufacturing and QC 9

Load max F<3.7 kG (Dubna 806 straws)

Breaking force for straws

0

0,05

0,1

0,15

0,2

0,25

2,25 2,75 3,25 3,75 4,25 4,75 5,25 5,75 6,25 6,75 7,25 7,75

Breaking force, kg

dN/N

F min = 2.5 kG /10mmF max = 7.75 kG/10mm (K ~ 3, K=max/min)

Rejected straws: N = 28 straws

F=3.7 kG

Blue – start strawRed – end straw

Apr 21, 2023 S.Movchan Straw manufacturing and QC 10

Load max F<3.7 kG (Dubna 806 straws)

Breaking force vs elongation (Corrected value)

y = 3,18x0,25

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

0,00 2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00 18,00

Elongation, mm

Bre

ak

ing

fo

rce

, kg

Blue – start strawRed – end straw

CERN straw rejection criteria: Load max L ≤ 3.7 kG (Strength ≤ 100 Mpa)

Rejected straws: N = 28 straws (~ 3.5 %)

and we have 7 straws (~ 1%) with elongation less than 1 mm

Rejected straws: N= 28 straws

BUT

F=3.7 kG

7 straws (~ 1% ) are with elongation less than 1 mm

Apr 21, 2023 S.Movchan Straw manufacturing and QC 11

dL < 1 mm (Dubna 806 straws)

Breaking force vs elongation (Corrected value)

y = 3,18x0,25

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

0,00 2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00 18,00

Elongation, mm

Bre

ak

ing

fo

rce

, kg

Blue – start strawRed – end straw

Rejected straws: N= 15 straws

Dubna straw rejection criteria: elongation dL < 1 mm

Rejected straws: N = 15 straws ( ~ 2 %)

and all good straws have elongation more than dL ≥ 1 mm !!!!!

dL=1 mm

Apr 21, 2023 S.Movchan Straw manufacturing and QC 12

dL < 1 mm @ Load max < 3.7 kG (Dubna 806 straws)

Breaking force vs elongation (Corrected value)

y = 3,18x0,25

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

0,00 2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00 18,00

Elongation, mm

Bre

ak

ing

fo

rce

, kg

Blue – start strawRed – end straw

Rejected straws: N= 56 straws

Dubna straw rejection criteria: elongation dL < 1 mm @ L < 3.7 kG

Total rejected straws: N = 35 straws (~ 4 %)

and all good straws have elongation more than dL ≥ 1 mm @ L > 3.7 kG

dL=1 mm

F=3.7 kG

Apr 21, 2023 S.Movchan Straw manufacturing and QC 13

ConclusionBoth CERN and Dubna proposed criteria for straw rejection were tested on Dubna straws. Was shown that:

- rejection criteria Load max F < 3.7 kG (Strength=100 Mpa) is wrong due to ~ 1 % of straws (7 straws out from 800) have elongation less than dL=1 mm

- rejection criteria dL < 1 mm is correct. Number of rejected straws are N = 18 straws ( ~ 2 %)

- combine criteria dL < 1 mm @ Load max F < 3.7 kG was tested too. Number of rejected straws are N = 35 straws ( ~ 4 %)

2 criteria and are tested and acceptable

-------Sefar straws:

Straw sample elongation was not fixed during tensile test. So, straw rejection criteria can not be correctly tested. Elongation must be measure too.

“soft”

“hard”

wrogn

“soft” “hard”

Apr 21, 2023 S.Movchan Straw manufacturing and QC 14