torsion and mechanical tests

8/13/2019 Torsion and Mechanical Tests

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M.Ferraris-35th ICACC

Daytona Beach , FL

Torsion tests for joined

ceramics and composites

Andrea Ventrella, Milena Salvo,Massimiliano Avalle, Monica Ferraris*

Politecnico di Torino, Italy


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Daytona Beach , FL

shear tests on joined

materials..


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Daytona Beach , FL


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Daytona Beach , FL

CONs:

Notches are needed ifthe joint strength is

high......

(joint) < 25% (ceramic) (ASTM C 1161)

25%< (joint)


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Daytona Beach , FL

Results on C/C joined by AV199 epoxy resin:

4 point symmetrical bending strength of joined C/C is44%the 3 point bending strength on C/C : V-notches

are needed to use asymm. 4 point bending test on C/C

joined by an adhesive !

Flessione a 4 Punti Simmetrica (giuntati)

0

20

40

60

80

0 10 20 30 40 50 60

s [m]

max[MPa]

4 point bending test on joined C/C -

ASTM C 1341

L = 40 mm

Lc= 20

mm

Flessione a 3 Punti (composito)

0

20

40

60

80

100

120140

160

0 5 10 15 20 25 30

Numero provino

max

[MPa]

3 point bending tests on C/C - ASTM C 1341

L = 20 mm


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Daytona Beach , FL

4 point symmetrical bending strength of joined SiC is 22,3%the 4 point bending strength on SiC

.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

180.00

200.00

.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00Joint thichkness

V-notches are needed to use asymm. 4 point

bending test on SiC joined with an adhesive !

bending=92,734

Results on SiC joined by AV199 epoxy resin:

MPa

415 MPa


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Daytona Beach , FL

X

ZY

Comparison of shear strength tests

A4PB

Asymmetrical four-point bending test (ASTM C1469)

TC

Torsion cylinder

TT

Torsion TubeTS

Torsion square

THG

Torsion hour-glass

DN

Double notchedASTM C1292-00 & C1425-99

SLO

single lap offsetASTM D905-03 DLODouble-lap offsetSL

Single lap offsetBT

Brazilian testASTM B 898

project involvingORNL (USA), Kyoto

University (Japan)

and Politecnico di

Torino (Italy)


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Daytona Beach , FL

X

ZY

Comparison of shear strength tests

A4PB


TCTorsion cylinder

TTTorsion Tube

TSTorsion square

THGTorsion hour-glass

DNDouble notched ASTMC1292-00 & C1425-99

SLOSingle lap off set

DLODouble-lap offset

SLSingle lap offset

BTBrazilian test

4

3

18

10

10

10

10

o10

i810

5

25

12

5

10

3

5

10

10

6

10

5

6

15

3

15

15

44

30

ASTM B 898

the adhesive is a

model joining

material to obtaina large number of

joined samples in

reasonable time

SiC , Al2O3,

C/C joined by

an adhesive(epoxy resin -

Araldite AV

119)

A4PB



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M.Ferraris-35th ICACCDaytona Beach , FL

4P- Asy:

Notches needed, not suitable for

strong joints, pure shear

different

tests give

different

results on

identicalsamples

PROs and

CONs ofeach test

for a

specific

joint must

be

evaluated

Single lap (SL):Critical alignment joint/fixturesNot suitable for strong joints

Double notched (DN) :

Critical role of notches

Single lap off set (SLO):Critical role of lateral fixtures

Double lap off set (DLO)Underestimated values

B 898:

Huge amount of material

needed

Brazilian:

Shear value not straightforward

M. Ferraris et al.,Composites: Part B 41 (2010) 182191

A. Ventrella et al.,J Mater Sci (2010) 45:44014405

E. Martin et al.,submitted to Materials Characterization(2010)

C/C test C i test


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C/C testefficiency

%

Ceramics testefficiency

%

DN 16,29 3,30

(33,02 4,98 *)

80%

TS Not suitable 0% Not suitable 0%

TC 19.7 5.4 70% 53,79.4 80%

BT 322.6

B898 22,26.67

SL 18.3 1.9(10.452.68 *)

55% 45,8 3,5 25 %

SLO 20.42.0

(28,002,15*)

80 % 52.36 75%

DLO 12.2 0.9 85% 29.47.6 70%

test efficiency % (number of samples broken inside the joint /

total number of prepared samples, %)

( *) = misplaced notches for DN, misaligned fixtures forSL, fixture-sample friction for SLO

C/C Multiplicativefactor

Ceramics

TC 19.7 5.4 x 2.5 ~ 53,79.4

SL 18.3 1.9 x 2.5 ~ 45,8 3,5

SL

O

20.42.0 x 2.6 ~ 52.36

DL

O

12.2 0.9 x 2.4 ~ 29.47.6


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ASTM F734-

95(2006) andF1362-97(2003)

Torsion

Test

Test rig for the torsion test


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M. Ferraris


torsion tests for joined CMC

and ceramics:


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Torsion Tests on epoxy

joined SiC tubes

t= ??? MPa

i


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Politecnico di Torino =67 MPa

THG SiCTHG SiC

THG SiC (Kyoto University) =66 MPa

THG SiC

THG SiC =66,42 MPa

Torsion Tests on epoxy

joined SiC hour glasses


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Torsion Test: summary

m

THG t=66,42 MPa

TC t=63,8 MPa

TT t =27,3 MPa

t =65,11 MPa


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TC Linear fitting byy = 8,6506x - 36,412

THG Linear fitting byy = 5,8528x - 24,853

-4

-3

-2

-1

0

1

2

3.75 3.85 3.95 4.05 4.15 4.25 4.35 4.45 4.55

LnLn(1/(1-Fj)

Ln(max)

TC

THG


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X

ZY

Concluding remarks:

A4PB


TCTorsion cylinder

TTTorsion Tube

TSTorsion square

THGTorsion hour-glass

DNDouble notched ASTMC1292-00 & C1425-99

SLOSingle lap off set

DLODouble-lap offset

SLSingle lap offset

BTBrazilian test

4

3

18

10

10

10

10

o10

i810

5

25

12

5

10

3

5

10

10

6

10

5

6

15

15

44

30

ASTM B 898

15

3


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M.Ferraris-35th ICACCDaytona Beach FL

Thank you for yourattention !

[email protected]

http://www.composites.polito.it

M. Salvo,

V. Casalegno,S. Han,

S. Rizzo,

A. Ventrella,

F. Smeacetto,

& students

torsion and mechanical tests

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