strategies and technological challenges for realizing...
TRANSCRIPT
JISSE12November 9‐11, 2011
Tokyo JapanTokyo, Japan
Strategies and Technological Challenges For Realizing Lightweight Mass Production
Automobile by using CFRTPy g
Jun TakahashiThe University of Tokyo, Japan
What is the decisive factor to use CFRP in automobile ?
Driving performance ?
Fuel efficiency ?
Yes, but…
Of course yes, but…
Not rust property ?
Multifunction property ?
Aesthetics ?
Recyclability ?
Maybe yes, but…
…. (yawn)
…. (zzz)
You must be joking !Recyclability ?
Cost ?
You must be joking !
Yes, cost is the first and absolute condition ! Others are later.
2008 Population Total Primary Energy Supply Total Final Energy Consumption
OECD 1190 million 4.56 toe/capita 3.11 toe/capita
Non‐OECD 5498 million 1.24 toe/capita 0.86 toe/capita
ECD
ta) 1.6
Conversion loss
Sectional Energy Consumption of OECD and Non‐OECD countries
C ti i th
rgy Co
nsum
ption of OE
CD cou
ntrie
s (toe
/cap
it
0.6
0.8
1.0
1.2
1.4 ElectricityCombustibleGas OilCoal
Pow
er
atio
nSe
lf C
onsu
mpt
ion
Kerosene for heating
Raw materials for plastics
Consumption in the engine combustion
Sectiona
l Ene
ran
d Non
‐OEC
0.0
0.2
0.4
Elec
tric
al
Gen
era
ConversionLoss
IndustrySector
TransportSector
OtherSectors
Non‐EnergyUse
OECD Non OECD Non OECD Non OECD Non OECD Non
Raw materials for plastics, Asphalt, Lubricant
4000
4500transport sector (non-OECD)transport sector (OECD)on
s)
Oil consumption of the world and transport sector
1/40 of the world (affordable) oil reserves
1500
2000
2500
3000
3500bunker oilother sectors
Con
sumption(M
illion t
Just burned in transport
sector
0
500
1000
1973 1980 1990 1995 2000 2005
World Oil
Source: EDMC, Energy & Economic Statistics 2011
Raw materialof plastics
80
90
100car (private)car (commercial)bustruckair (domestic)
Energy Consumption Structure of Japanese Transport Sector
toe)
30
40
50
60
70air (domestic)ship (domestic)rail
ergy Con
sumption (M
t
0
10
20
1965 1970 1975 1980 1985 1990 1995 2000 2005
Ene
Source: EDMC, Energy & Economic Statistics 2011
Transition of Passenger Automobile Type in Japan
50
60
mob
ile
×106
executive
DrivingPerformance
Lamborghini,
20
30
40
k Num
ber o
f Autom
normalEco
TOYOTA “1/X” (HEV, 420kg)
g ,“Sesto Elemento” (999kg)
0
10
1970 1980 1990 2000
Stock
mini Eco
JARI “C・ta” (EV, 300kg)
Problem is not only cost but also production cycle time and recyclability.
Material costHi CF volume fractionExpensive resin
Material costLower CF volume fraction Inexpensive resin
< Thermosetting CFRP > < Thermoplastic CFRP >
Cost reduction of CFRP products by using thermoplastics
Manufacturing costMachine → mass productionOperation → out of autoclaveEmployees → automation
Manufacturing costMachineOperationEmployees
Expensive resin Inefficient prepreg system Ineffective utilization ratio of CF
Inexpensive resinEfficient prepreg systemEffective utilization ratio of CF
Manufacturing cost will be reduced by
automated high cycle molding technologyp y
Toolsp y
Toolsg gy
Effective measures for cost reduction Develop higher cycle manufacturing method Achieve required properties by lower Vf Establish advanced 3R system of CF
Current ( ave.1380kg, 200,000cars/y *1)*1) 800/day = 50/hour = cycle time is 1minute
Lightweight ◎Parts number ◎Cycle time ×Cost ×
Concept car (weight is 1/3)integration structure by thermoset CFRP
Global energy saving ?
Concept of automobile lightening for mass production
CFRTPBy using CFRTP sheet and tape high cycle press molding expansion into non‐automotive field
Then, Lightweight ◎
Recycle ×Safety ?
saving ?For EV ?
Project target (weight ▲30%, 200,000cars/y)Parts substitution by thermoplastic CFRP
Lightweight ◎ Cycle time ○ ← project theme Cost ○ ← project theme Recycle ○ ← project theme Safety ○ ← project theme
Immediate effect for not only energy saving but also waste management laws It contributes cost reduction, early spread, saving rear metals of electric vehicles It will extend to 60% weight reduction for mass production automobile
AdviserParticipants
Development of Sustainable Hyper Composite Materials Technology (2008-12)
Project LeaderProf. Jun TakahashiThe Univ. of Tokyo
Japanese National Program to Develop CFRTP for Mass Production Automobile
2008 – 2012fyTotal budget: 4 billion JPY (≒50 million US$)
1. CF/PP and CF/PA sheets surface treated CF and modified
thermoplastics continuous and discontinuous CF
reinforced sheets
2. High cycle molding technology press molding press molding bladder molding
3. Jointing technology between CFRTP with metal
4. Repair and recycling
ThermoplasticsCarbon Fiber Press in 1 minPre heat
Discontinuous fiber reinforced sheet
Isotropic preform technology
Cut
High cycle press molding
Impregnation
Dispersion
Isotropic preform
High cycle press molding
Carbon fiber
Intermediate substrate
Primary parts
Final parts
Raw materials
Continuous CF reinforced UD-tape and its various application
Cross sheet
Thermoplastic
UD sheet
UD + random
Pipe made by welding
Impregnation
Plate with stiffeners
Braiding
High cycle bladder moldingPrepreg tape
Random sheetRandom
Seamless pipe
welding
SeatDoor FrameFender Support
Front CowlRR luggage Partition
Hood Roof◆ Conventional car and CFRP car
Weight Reduction Concept by using CFRTP
1,500
)
CFRP
Others
Standard sedanCFRP
CFRP : 17%(174 kg)
Continuous CFRTP:Structural member such as frame
Discontinuous isotropic CFRTP
FR Engine Cover
Under Cover
Radiator Core Support
Energy AbsorptionPipe
RR luggage space
FR Dash
Door inner
(kg)
Body weight can be reduced by 30% with CFRTP application
0
500
1,000
Conventional CFRP car
車体
重量
(kg
Others
AL
Steel
Body weight1380→970kg (▲30%)
Steel968kg Steel
385kg
Discontinuous isotropic CFRTP: Panels, complex parts
Vehicle weight (
Automotive Materials and Structures
panel88%
frame12%
panel57%
frame30%
casting13%
< Monocoque body >Better structure for lightweight
< Frame monocoque hybrid body >Better for safety and recyclability
Automobile parts are mostly composed of plates. Flexural properties are dominant in the case of
automotive materials and structures.
Steel plate CF/PP plate Ratio to Steel
Elastic Modulus (E) ES = 200GPa EC = 25GPa (Vf=0.3, ISO) 1/8
Thickness (t) t 2t 2
Mechanism of one‐third weight reduction
Volume (V∝t) V 2V
2
Flexural stiffness(EI∝Et3) ES t3 EC (2t)3 1
Deformation (δ∝P/EI)
Load (P)
δ
Load (P)
δ
1same flexural performance
( )
=equalsSurface strain (ε) ε 2ε 2
Surface stress (σ) σS = ES*ε σC = EC*2ε 1/4
Buckling strength PS=π2 ESIS/L2 PC=π2 ECIC/L2 1
Density (ρ) 7.8 1.3 1/6
Weight (W) 7.8V 1.3*2V 1/3
CF/EP
Compressive Side
CF/PP
① BucklingCompressive Side
Difference between CFRTS and CFRTP
① Fiber breaking at tensile side
② Local plasticdeformation
② Delamination
③ Fiber breaking without delamination
① ① ②
Fracture mechanism of CFRTP is ductile in comparison with that of CFRTS.
Pδ
①
② P
δ
① ②③
Weak interface
Debonding
Difference in Fracture Process of Composite Materials
CF
Resin Load
Delamination= Reduction of sectional area (EI ∝Et3)
Strong interface (brittle resin)
Debonding
Load
Cleavage crackpropagation
CFComposites become easier to buckle by compressive load anddeform by flexural load
Strong interface (ductile resin)
propagation
Load
Load
DeformationShear fractureof resin
ー Steel Panelー CF/EP Panelー CF/PP Panel
Comparison of steel, CF/EP, and CF/PP panels
1. CFRP plate, which has the same flexural rigidity as steel plate, is 1/3 of the weight of the steel panel.
2 Elastic strain range of CFRP is larger thanCF/PP Panel
Flexural Loa
d
2. Elastic strain range of CFRP is larger than steel, hence CFRP is less likely to dent.
3. However, stress concentration part of CF/EPshows sudden load fall (i.e. brittle fracture). Hence CF/EP is weak in hole, notch, and corner. They are caused by delamination.
4. Since delamination doesn’t occur, CF/PP not only shows high energy absorption capacity
Flexural Deformation
y g gy p p ybut is stronger in hole, notch, and corner.
5. Additionally, CF/PP can easily bond, repair and recycling by using thermoplasticity.
6. By using these features of CF/PP, various novel structures and manufacturing methods can be developed.
0 5
0.6 ISO plate UD plate
Weight Lightening Ratio of CF/PP Plate to Steel Plate
to Steel
2 5
3.0
0 325
0.330 weight lightening ratiodensitytickness ratioGF/UP(Vf60‐iso) 0.58
Difference between isotropic and unidirectional CF/PP plate
Weight lightening ratio, density and thickness ratio of isotropic CF/PP plate
0.2
0.3
0.4
0.5
tening
Ratio of C
F/PP
t
1.0
1.5
2.0
2.5
0.310
0.315
0.320
0.325
Magnesium 0.39
CF/EP(Vf60‐iso) 0.31
Aluminum 0.50
0.0
0.1
0.0 0.1 0.2 0.3 0.4 0.5 0.6
Carbon Fiber Volume Fraction in CF/PP plate
Weight Light
0.0
0.5
0.300
0.305
0.0 0.1 0.2 0.3 0.4 0.5 0.6
referenceCF/EP(Vf60‐iso)
■ 0.31● 1.5 ◆ 1.6
Weight is the same or lighter than CF/EP
Inexpensive Impregnation becomes easier
Elastic strain range is not sufficient as a structural member
0 5
0.6
Weight of CF in CF/PP Plate
e
■ ISO CF/PP plate■ UD CF/PP plate
CF i ISO CF/PP l t
Automobile parts are mostly composed of flexural member.
0.2
0.3
0.4
0.5
t of C
F an
d CF/PP plate
▲ CF in ISO CF/PP plate▲ CF in UD CF/PP plate In the case of flexural member, steel
panel of 100 kg can be replaced by CF/PP panel (isotropic, Vf=0.2) of 32 kg in which just 10 kg of CF is used.
In the case of tensile/compressive member, the same weight lightening
0.0
0.1
0.0 0.1 0.2 0.3 0.4 0.5 0.6
Carbon Fiber Volume Fraction
Weigh
member, the same weight lightening ratio and CF usage rate can be achieved by anisotropy and higher Vf.
Effective utilization of carbon fiber and efficient joint are indispensable to reduce both weight and cost.
Market50 – 70 %
Raw CF100 %
Industrial waste30 – 50 %
‐‐‐‐‐‐‐‐‐‐‐waste at trimming ‐‐‐‐‐‐‐‐‐‐‐
How to reduce or reuse the industrial waste of CFRP ?
Plate recycle(f d t t
‐‐ storage loss ‐‐
‐‐‐‐‐‐‐‐ NG parts ‐‐‐‐‐‐‐‐
(from edge waste to moldable plate or sheet)
In‐houseRepair
(by heating)
No storage loss
Shop repair(by heating)
‐‐‐‐‐ quality assurance inspection ‐‐‐‐‐
(by heating) loss
Crushed recycleto high performance secondary member(by using strong resin‐fiber adhesion)
NG‐Parts
RawMaterials
Intermediatematerial Parts Products EOL
vehicle
B
Life Cycle of CFRTP in Automobile and Possibility of 3R
CF
TP
CFRTP
HG‐waste
C DamagedA
D (Hybrid recycling)
reuse
reuse
LG‐wasteLG‐waste
A: Plate recycling, Hybrid recyclingB: In‐house repairC: Shop repairD: Reuse, Hybrid recycling
A
Schematics of CFRTP recycling
WithoutGlue
Panel with only recycled CF/PP
Panel with fresh CF/PP
Double Belt PressRecycledPlate Fresh Sheet
Hybrid Stamping
Injection Molding
1000
1200 0.80.91.0
The Amount of CF Usage and Automotive Lightening Ratio
Steel Car of 1380 kg is composed byweight fixed part = 200 kgreplaceable part = 900 kgut
omob
ile
kg)
0
200
400
600
800
1000
0.00.10.20.30.40.50.60.7
replaceable part = 900 kgproportionally lightening = 280 kg
The amount of CF usage = x kg→ CFRP = 2x kg→ replaced steel = 6x kg
where, 0≦6x≦900 kg
ht Lightening
Ratio of A
u
Automotive weight (k
By usinganisotropic
0 20 40 60 80 100 120 140 Automotive weight after lightening= 1380‐1180*(4x/900)
Automotive weight lightening ratio = 1‐0.0038 x
Weigh
The Amount of CF Usage (kg)
Trade‐off between cycle time and weight lightening ratio
Flexural stiffness Torsional stiffness WeightIsotropic 152 210 151kg
Anisotropic 200 286 151kgAnisotropic 200 286 151kg
unit passengerautomobile truck wind turbine
bladecommercial airplane (L)
world stock 103700,000@2010
1,000,000@2030
1,300,000@2050
260,000@2010
380,000@2030
500,000@2050
120@2010
1,000@2030
1,500@2050
15@2010
30@2030
45@2050
53 000@2010 20 000@2010 25@2010 0 6@2010D ti i f b fib J N ti l
World carbon fiber Potential demand by application
world annualproduction 103
53,000@2010
75,000@2030
100,000@2050
20,000@2010
30,000@2030
40,000@2050
25@2010
50@2030
60@2050
0.6@2010
1.2@2030
1.8@2050
CF demandper product ton 0.1 0.4 4 25
world annualCF demand
103 tonsper year
5,300@2010
7,500@2030
10,000@2050
8,000@2010
12,000@2030
16,000@2050
100@2010
200@2030
240@2050
15@2010
30@2030
45@2050
200 000 50 000 5 000 300
Drastic increase of carbon fiber production capacity is necessary
Japanese National Project 2011‐2015
production volumeper plant
per year 200,000 50,000 5,000 300per day 800 200 20 1.2per hour 50 13 1.25 0.075
number of plants(Assuming an ideal production plant)
265@2010
375@2030
500@2050
400@2010
600@2030
800@2050
5@2010
10@2030
12@2050
2@2010
4@2030
6@2050
CF demandper plant
103 tonsper year 20 20 20 7.5
Drastic high cycle manufacturing technology of CFRP is necessary
Japanese National Project 2008‐2012
2008 Population Total Primary Energy Supply Total Final Energy Consumption
OECD 1190 million 4.56 toe/capita 3.11 toe/capita
Non‐OECD 5498 million 1.24 toe/capita 0.86 toe/capita
ECD
ta) 1.6
Conversion loss
Promising target for massive application of CFRPFossil resource reduction in
power generation
Fossil resource reduction by
weight reduction &EARLY SPREAD of EV
Extension of flight range
rgy Co
nsum
ption of OE
CD cou
ntrie
s (toe
/cap
it
0.6
0.8
1.0
1.2
1.4 ElectricityCombustibleGas OilCoal
Pow
er
atio
nSe
lf C
onsu
mpt
ion
Oil consumption for additional CF
production is less than 0.01 toe/capita
Sectiona
l Ene
ran
d Non
‐OEC
0.0
0.2
0.4
Elec
tric
al
Gen
era
ConversionLoss
IndustrySector
TransportSector
OtherSectors
Non‐EnergyUse
OECD Non OECD Non OECD Non OECD Non OECD Non
Thank you for your kind attentionThank you for your kind attention.