Torsion tests for joined
ceramics and composites
Andrea Ventrella, Milena Salvo,
Massimiliano Avalle, Monica Ferraris*
Politecnico di Torino, Italy
M.Ferraris-35th ICACC
Daytona Beach , FL
shear tests on joined
materials…..
M.Ferraris-35th ICACC
Daytona Beach , FL
M.Ferraris-35th ICACC
Daytona Beach , FL
State of the art: ASTM C1469
Asymmetrical four-point bending
(joint) < 25% (ceramic) (ASTM C 1161)
CONs:
•Notches are needed if
the joint strength is
high......
25%< (joint)<50% (ceramic) (ASTM C 1161)
withoutU-notch
notches
V-notch
18x4x3 mm
M.Ferraris-35th ICACC
Daytona Beach , FL
Results on C/C joined by AV199 epoxy resin:
4 point bending test on joined C/C Flessione a 4 Punti Simmetrica (giuntati)
ASTM C 1341
Flessione
a 3 Punti
(composito)
3 point bending
tests
on C/C
- ASTM C 1341
160
80
σmax [MPa]
σmax [MPa]
140
120
100
80
60
40
20
60
40
20
0
0
0
5
10
15
Numero provino
20
25
30
0
10
20
30
40
s [μm]
Lc = 20
mm
L = 20 mm
L = 40 mm
4 point symmetrical bending strength of joined C/C is
44% 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 !
M.Ferraris-35th ICACC
Daytona Beach , FL
50
60
Results on SiC joined by AV199 epoxy resin:
 bending =92,7±34
200.00
180.00
MPa
160.00
140.00
120.00
100.00
80.00
415 MPa
60.00
40.00
20.00
.00
.00
50.00
100.00
150.00
200.00
250.00
300.00
350.00
Joint thichkness
4 point symmetrical bending strength of joined SiC is 22,3%
the 4 point bending strength on SiC
V-notches are needed to use asymm. 4 point
bending test on SiC joined with an adhesive !
M.Ferraris-35th ICACC
Daytona Beach , FL
Comparison of shear strength tests
Y
project involving
ORNL (USA), Kyoto
University (Japan)
and Politecnico di
Torino (Italy)
Z
X
TS
Torsion square
A4PB
Asymmetrical four-point bending test (ASTM C1469)
TC
TT
THG
Torsion cylinder
Torsion Tube
Torsion hour-glass
SLO
DN
single lap off
DLO
SL
M.Ferraris-35th
Double notched ICACC
set ASTM D905-03 Double-lap offset Single lap offset
Daytona
ASTM C1292-00
& C1425-99 Beach , FL
ASTM B
898
BT
Brazilian test
Comparison of shear strength tests
4
3
Y
Z
18
A4PB
A4PB
Asymmetrical
four-point
bending
(ASTM
C1469)
Asymmetrical
four-point
bending
testtest
(ASTM
C1469)
X
10
 10
o 10
10
TS
TC
TT
Torsion square
Torsion cylinder
Torsion Tube
6
5
25
10
10
3
DN
THG
Torsion hour-glass
5
12
5
i 8
10
10
ICACCSLO
DoubleM.Ferraris-35th
notched ASTM
C1292-00Daytona
& C1425-99
Beach , Single
FL lap off set
4
Double-lap offset
30
3
10
DLO
4
6
10

15
5
SL
Single lap offset
15
15
ASTM B 898
BT
Brazilian test
Comparison of shear strength tests
SiC , Al2O3,
C/C joined by
an
Y adhesive
(epoxyZ resin AralditeX AV
119)
4
3
18
A4PB
A4PB
Asymmetrical
four-point
bending
(ASTM
C1469)
Asymmetrical
four-point
bending
testtest
(ASTM
C1469)
10
 10
o 10
10
TS
TC
TT
Torsion square
Torsion cylinder
Torsion Tube
6
5
10
10
3
DN
THG
Torsion hour-glass
5
12
5
i 8
10
10
25
the adhesive is a
“ model” joining
material to obtain
a large number of
joined samples in
reasonable time
ICACCSLO
DoubleM.Ferraris-35th
notched ASTM
C1292-00Daytona
& C1425-99
Beach , Single
FL lap off set
4
Double-lap offset
30
3
10
DLO
4
6
10

15
5
SL
Single lap offset
15
15
ASTM B 898
BT
Brazilian test
•different
tests give
different
results on
identical
samples
•PROs and
CONs of
each test
for a
specific
joint must
be
evaluated
Single lap (SL):
Critical alignment joint/fixtures
Not suitable for strong joints
Double notched (DN) :
Critical role of notches
Double lap off set (DLO)
Underestimated values
Single lap off set (SLO):
Critical role of lateral fixtures
B 898:
Huge amount of material
needed
Brazilian:
Shear value not straightforward
Composites: Part B 41 (2010) 182–191
•A. Ventrella et al., J Mater Sci (2010) 45:4401–4405
•E. Martin
et al., submitted
to Materials Characterization
M.Ferraris-35th
ICACC
(2010) Daytona Beach , FL
•M. Ferraris et al.,
4P- Asy:
Notches needed, not suitable for
strong joints, pure shear
test
test
C/C
Ceramics
efficiency
test efficiency % (number of samplesefficiency
broken inside the joint
/
%
%
total number of prepared samples, %)
DN
16,29 ± 3,30
(33,02 ± 4,98 *)
TS
Not suitable
TC
5.45.4
TC19.7±
19.7±
70%
x 2.5
~53,7±9.453,7±9.4
18.3 ± 1.9
x 2.5
45,8 ±3,5
~
32±2.6
B898
SL 20.4±2.0
O 22,2±6.67
x 2.6
~
SL
DL18.3
12.2
± 0.9
± 1.9
O (10.45± 2.68 *)
x 2.4
55%
29.4± 7.6 25 %
~45,8 ±3,5
80 %
52.3± 6
C/C
SL
80%
0%
BT
SLO
DLO
M.Ferraris-35th ICACC
Daytona Beach , FL
20.4±2.0
(28,00±2,15*)
Not suitable
Multiplicative
factor
0%
Ceramics
80%
52.3± 6
75%
12.2 ± 0.9
85%
29.4± 7.6
70%
( *) = misplaced notches for DN, misaligned fixtures for
SL, fixture-sample friction for SLO
Torsion
Test
Test rig for the torsion test
ASTM F73495(2006) and
F1362-97(2003)
M.Ferraris-35th ICACC
Daytona Beach , FL
torsion tests for joined CMC
and ceramics:
M. Ferraris
M.Ferraris-35th ICACC
Daytona Beach , FL
Torsion Tests on epoxy
joined SiC tubes
t = ??? MPa
M.Ferraris-35th ICACC
Daytona Beach , FL
Torsion Tests on epoxy
joined SiC hour glasses
THG
THGTHG
SiC
SiC SiC
THG SiC
(Kyoto
University)
THG
SiC =66,42
MPa =66 MPa
Politecnico di Torino =67 MPa
M.Ferraris-35th ICACC
Daytona Beach , FL
M.Ferraris-35th ICACC
Daytona Beach , FL
Torsion Test: summary
THG t =66,42 MPa
t =65,11 MPa
TC t =63,8 MPa
TT t =27,3 MPa
μm
M.Ferraris-35th ICACC
Daytona Beach , FL
3.75
2
3.85
3.95
4.05
4.15
4.25
4.35
4.45
4.55
TC Linear fitting by
y = 8,6506x - 36,412
1
THG Linear fitting by
y = 5,8528x - 24,853
LnLn(1/(1-Fj)
0
-1
TC
THG
-2
-3
-4
M.Ferraris-35th ICACC
Daytona Beach , FL
Ln(τmax)
Concluding remarks:
4
3
Y
Z
18
A4PB
Asymmetrical four-point bending test (ASTM C1469)
X
10
 10
o 10
10
TS
TC
TT
Torsion square
Torsion cylinder
Torsion Tube
6
5
25
10
10
3
DN
THG
Torsion hour-glass
5
12
5
i 8
10
10
M.Ferraris-35th ICACCSLO
Double notched ASTM
Beach , Single
FL lap off set
C1292-00Daytona
& C1425-99
4
Double-lap offset
30
3
10
DLO
4
6
10

15
5
SL
Single lap offset
15
15
ASTM B 898
BT
Brazilian test
Thank you for your
attention !
monica.ferraris@polito.it
http://www.composites.polito.it
M.Ferraris-35th ICACC
Daytona Beach , FL
M. Salvo,
V. Casalegno,
S. Han,
S. Rizzo,
A. Ventrella,
F. Smeacetto,
& students