Durability of Aircraft Structural Composites Processed by ... · Material technologies ...
Transcript of Durability of Aircraft Structural Composites Processed by ... · Material technologies ...
Durability of Aircraft Structural Composites Processed by VaRTM
Masahiro Moriyama, Kenichi Yoshioka, Akihiko KitanoToray Industries, Inc.
2
Contents
1. Background2. Fatigue Tests
i. OHC : Open Hole Compressionii. CAI : Compression After Impact
3. Environmental Exposure Testsi. Temperature Exposureii. Moisture Exposureiii. Thermal Cycle Exposureiv. Hygrothermal Cycle Exposure
4. Modeling of Fatigue Damage Propagation5. Conclusion
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CFRP Aircraft Structures
CFRP Ratio in Aircraft Structures
CFR
P W
eigh
t Rat
io in
Str
uctu
re [w
t%]
First Flight Year
1995 1970 1975 1980 1985 1990 2000
100
80
60
40
20
0 2005 2010
F14 F15
S76
Learfan 2000
Avtek 400
Voyager
V22
LHK Stership
F16 F18
AV8B
B757
B767 A310
X29
ATR42 A300
EAP Rafal
JAS39
ATF
Rafal D
A320
ATR72
A340 B777
Rotorcraft Business jets
Smallaircraft
Largeaircraft
A340-600
A380
B787
1. Background
4
CFRP Fabrication Process
Common applications:
Trucks, Boats, Building structures, etc.
Large and complex parts Low costLow energy consumption
Prepreg / autoclave process (conventional)
De-molding
Resin prepreg
Autoclave
CFRP
Bagging Cure Prepregging Lay-up CF
Filming
Bagging film
CF
Resin Bagging film
Pump CFRP De-molding Bagging Cure Lay-up
VaRTM (Vacuum-assisted Resin Transfer Molding)
Advantage of VaRTM Process
Disadvantage of VaRTM Process CFRP properties
1. Background
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A-VaRTM
VaRTMLarge and complex parts, Low cost
Trucks, Boats, Building Structures, etc.
Fabrication technologies<Toray>
<Mitsubishi Heavy Industries>
Material technologies<Toray>
Advanced-VaRTM“A-VaRTM”
Large and complex parts, Low cost, Low energy consumption High performance
Aircraft primary structural elements
A-VaRTM Definition
Problem of A-VaRTM
Insufficient durability data compared with traditional materials
1. Background
6
Summary
・Fatigue tests (CAI, OHC)
・Environmental exposure tests (assumed for aircraft use)
1. Acquiring durability data of A-VaRTM
2. Modeling of fatigue damage propagation
・Damage detection of OHC fatigue specimen
・Life prediction of OHC fatigue
Objective:Long-term degradation model of A-VaRTM
1. Background
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OHC Fatigue Test Results2. Fatigue Data
305
Hol
e D
iam
eter
:6.3
5
38.1
Unit:mmCompression-CompressionR = 10 f = 5Hz
Stacking Sequence:[45/0/-45/90] 2S
0
10
20
30
40
50
1 10 102 103 104 105 106
Cycles to Failure
Min
imum
Stre
ss [k
si]
T800H/3900-2 (G145)
CZ8433DP/TR-A37
σmin
σmax
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CAI Fatigue Test Results2. Fatigue Data
0
10
20
30
40
50
1 10 102 103 104 105 106
Cycles to Failure
Min
imum
Stre
ss [k
si]
T800S/3900-2B
CZ8433DP/TR-A37
270in-lbs
720in-lbs
Compression-CompressionR = 10 f = 5Hz σmin
σmax
Stacking Sequence:[45/0/-45/90] 3S
152.
4
101.6
Unit:mm
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1. Temperature Exposure
4. Hygrothermal Cycle Exposure
t
T
100°C
t
T
60°C / 85%RH
2. Thermal Cycle Exposure
3. Moisture Exposure
3. Environmental Resistance Data
3min t
T
RT
-54℃
100℃
10min 3min
10min
(125℃ for T800S/3900-2B)
-55°C
82°C
t
T
35°C 95%RH
24min 24min 72min
(Condition of T800S/3900-2B)
t
T
49ºC/95%RH 12h
within 24hr -54ºC 5min
36min (1cycle )
-54ºC
T
60min
71ºC 5min
Conditions of Environmental Exposure
Conditions of environmental exposure were based on durability study of T800S/3900-2B.
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Composite Testing1. CAI
2. OHC
3. IPS
[45/0/-45/90]3sImpact enegy = 30.5J (270in-lb)Deflection rate = 1.27mm/min
[45/0/-45/90]2sDeflection rate = 1.27mm/min
[45/-45]2sDeflection rate = 1.27mm/min
Mechanical properties were measured before and after environmental exposure.
3. Environmental Resistance Data
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CZ8433DP/TR-A37
Test Matrix of Environment Exposure Tests 3. Environmental Resistance Data
0cycle400cycles
2000cycles
4. Hygrothermal Cycle Exposure[49℃/95%RH→-54℃→71℃]
0hr1000hrs3000hrs
3. Moisture Exposure[60℃/85%RH]
0cycle3000cycles
2. Thermal Cycle Exposure[-54℃→100℃]
0hr3000hrs
1. Temperature Exposure[100℃]
IPSOHCCAI
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Temperature Exposure [ 100℃]
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [hrs]
CA
I [ks
i]
T800S/3900-2B
CAI After Temperature Exposure
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [hrs]
CA
I [ks
i]
CZ8433DP/TR-A37
Average of blank specimen
3. Environmental Resistance Data
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0
10
20
30
40
50
0 1000 2000 3000 4000Exposure period [hrs]
OH
C [k
si]
OHC After Temperature Exposure
T800S/3900-2B
10
20
30
40
50
0 1000 2000 3000 4000Exposure period [hrs]
OH
C [k
si]
CZ8433DP/TR-A37
Temperature Exposure [ 100℃]
3. Environmental Resistance Data
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0
5
10
15
20
25
0 1000 2000 3000 4000Exposure period [hrs]
In-p
lane
she
ar s
treng
th [k
si]
IPS Strength After Temperature Exposure
T800S/3900-2B
Exposure period [hrs]
0
5
10
15
20
25
0 1000 2000 3000 4000
In-p
lane
she
ar s
treng
th [k
si]
CZ8433DP/TR-A37
Temperature Exposure [ 100℃]
3. Environmental Resistance Data
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CAI After Thermal Cycle Exposure
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [cycles]
CA
I [ks
i]
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [cycles]
CA
I [ks
i]
T800S/3900-2B CZ8433DP/TR-A37
3. Environmental Resistance Data
Thermal Cycle Exposure [-54℃→125 or 100℃]
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OHC After Thermal Cycle Exposure
10
20
30
40
50
0 1000 2000 3000 4000Exposure period [cycles]
OH
C [k
si]
10
20
30
40
50
0 1000 2000 3000 4000Exposure period [cycles]
OH
C [k
si]
00
T800S/3900-2B CZ8433DP/TR-A37
3. Environmental Resistance Data
Thermal Cycle Exposure [-54℃→125 or 100℃]
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IPS Strength After Thermal Cycle Exposure
Exposure period [cycles]
0
5
10
15
20
25
0 1000 2000 3000 4000
In-p
lane
she
ar s
treng
th [k
si]
Exposure period [cycles]
0
5
10
15
20
25
1000 2000 3000 4000
In-p
lane
she
ar s
treng
th [k
si]
0
T800S/3900-2B CZ8433DP/TR-A37
3. Environmental Resistance Data
Thermal Cycle Exposure [-54℃→125 or 100℃]
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Moisture Exposure [60℃/85%RH]
CAI After Moisture Exposure
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [hrs]
CA
I [ks
i]
0
10
20
30
40
50
60
0 1000 2000 3000 4000Exposure period [hrs]
CA
I [ks
i]
T800S/3900-2B CZ8433DP/TR-A37
3. Environmental Resistance Data
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OHC After Moisture Exposure
10
20
30
40
50
0
OH
C [k
si]
01000 2000 3000 4000
Exposure period [hrs]
T800S/3900-2B CZ8433DP/TR-A37
10
20
30
40
50
0
OH
C [k
si]
01000 2000 3000 4000
Exposure period [hrs]
Moisture Exposure [60℃/85%RH]
3. Environmental Resistance Data
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IPS Strength After Moisture Exposure
Exposure period [hrs]
0
5
10
15
20
25
1000 2000 3000 4000
In-p
lane
she
ar s
treng
th [k
si]
0
T800S/3900-2B
Exposure period [hrs]
0
5
10
15
20
25
1000 2000 3000 4000
In-p
lane
she
ar s
treng
th [k
si]
0
CZ8433DP/TR-A37
Moisture Exposure [60℃/85%RH]
3. Environmental Resistance Data
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CAI After Hygrothermal Cycle Exposure
0
10
20
30
40
50
60
CA
I [ks
i]
0 500 1000 1500Exposure period [cycles]
T800S/3900-2B
0
10
20
30
40
50
60
0 500 2500Exposure period [cycles]
CA
I [ks
i]
1000 1500 2000
CZ8433DP/TR-A37
3. Environmental Resistance Data
Hygrothermal Cycle Exposure [-55℃→35℃/95%RH→82℃ or 49℃/95%RH→-54℃→71℃]
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OHC After Hygrothermal Cycle Exposure
10
20
30
40
50
0
OH
C [k
si]
0 1000 2500
Exposure period [cycles]
10
20
30
40
50
0
OH
C [k
si]
0500 1000 1500
Exposure period [cycles]
T800S/3900-2B
500 1500 2000
CZ8433DP/TR-A37
3. Environmental Resistance Data
Hygrothermal Cycle Exposure [-55℃→35℃/95%RH→82℃ or 49℃/95%RH→-54℃→71℃]
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IPS Strength After Hygrothermal Cycle Exposure
0
5
10
15
20
25
In-p
lane
she
ar s
treng
th [k
si]
0 500 1000 1500Exposure period [cycles]
T800S/3900-2B
0
5
10
15
20
25
In-p
lane
she
ar s
treng
th [k
si]
0 500 1000 2500Exposure period [cycles]
20001500
CZ8433DP/TR-A37
3. Environmental Resistance Data
Hygrothermal Cycle Exposure [-55℃→35℃/95%RH→82℃ or 49℃/95%RH→-54℃→71℃]
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CT Image of OHC Fatigue Specimen
Fatigue behavior is dominated by delamination from the microbacking.
0.5mm
0% 50% 65%
80% 95%
0°
90°
0° 0° 0°
0° 0°
Microbackling
Delamination
Delamination growth
Tool side
Viewpoint
σmin=0.775σ0(Fatigue life is about 71,000 cycles.)
4. Modeling
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y = 2E-55x21.27
1.0E-11
1.0E-10
1.0E-09
1.0E-08
1.0E-07
1.0E-06
1.0E-05100 1000
∆GI[J/m2]
da/d
N[m
/cyc
le]
Life Prediction of OHC FatigueAnalytical model
σ0
5mm
x
Distribution of σy
y
Delamination
σ0
6mm
6.35mm
a0=2mm
5mm
a1=6mm
σy=1.5σ0
σy=1.5σ0
Cross-section
Two delaminations
(1)Overview
(2)Analytical model
Analytical solution for fatigue life
∫ ∆=
1
0)(
a
anf Gm
daN
Nf:Cycles to failurea0:Initial delamination lengtha1:Final delamination lengthΔG:Energy release ratem,n:Fitting parameter
Fitting parameters were determined from da/dN plot during DCB and ENF fatigue tests.
4. Modeling
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Analytical Result
Analytical result is in good agreement with experimental result.
S-N Curve (OHC)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1 10 100 1000 10000 100000 1000000
Cycles to Failure
Nor
mal
ized
Stre
ss
Experimental Data
Analysis
4. Modeling
27
Conclusion
Fatigue TestsOHC and CAI fatigue behavior of A-VaRTM material is similar to that of aerospace grade prepreg.
Environmental Exposure TestsMechanical properties of A-VaRTM material exhibited little degradation after environmental exposure tests.This is similar to that of aerospace grade prepreg.
Modeling of Fatigue Damage PropagationOHC fatigue behavior of A-VaRTM material is dominated by delamination from the microbackling of 0 degree layer.By parameterizing energy release rate and delamination length, analytical result of OHC fatigue life was in good agreement withexperimental result.