Development of CFRTP for Mass Produced Automobile

CDW‐15, Kanazawa, JapanOctober 18‐19, 2010

Jun Takahashi, Kiyoshi Uzawa and Tsuyoshi MatsuoThe University of Tokyo, Japan

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ElectricityCombustibleGasOilCoal

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iona

l Ene

rgy

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umpt

ion

of O

ECD

an

d N

on‐O

ECD

cou

ntri

es (t

oe/c

apita

)Population Total Primary Energy Supply Total Final Energy Consumption

OECD 1154 million 4.67 toe/capita 3.25 toe/capita

Non-OECD 5114 million 1.04 toe/capita 0.69 toe/capita

ConversionLoss

IndustrySector

TransportSector

OtherSectors

Non‐EnergyUse

OECD Non OECD Non OECD Non OECD Non OECD Non

Sectional Energy Consumption of OECD and Non‐OECD countries (2003)

Energy Consumption Structure of Japanese Transport Sector

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1965 1970 1975 1980 1985 1990 1995 2000

Energ

y C

onsu

mption in

Tra

nsp

ort

ation S

ecto

r (M

toe)

Car (Private)Car (Business)BusTruckAirplaneShipRailway

CFRTPBy using sheet and tape

high cycle press moldingexpansion into non‐automotive field

Then,Lightweight ◎Cycle time ○ ← project themeCost ○ ← project themeRecycle ◎ ← project themeSafety ○ ← project theme

Concept of automobile lightening for mass production

Immediate effect for not only energy saving but also waste management lawsIt contributes cost reduction, early spread, saving rear metals of electric vehiclesIt will extend to 60% weight reduction mass produced automobile

Current ( ave.1380kg, prod.20,000/y *1)*1) 800/day = 50/hour = cycle time is

1minuteLightweight ◎Parts number ◎Cycle time ×Cost ×Recycle ×Safety ？

Concept car (weight is 1/3)integration structure by thermoset CFRP

Global energy saving ?For EV ?

Project target (weight ▲30%, prod. 20,000/y)Parts substitution by thermoplastic CFRP

Body weight can be reduced by 30% with CFRTP application

Standard vehicle

CFRTP

Body weight1380→970kg （▲30%）

Discontinuous CFRTP：Panels, ModulesContinuous CFRTP ：Structures

SeatDoor Frame

FR Engine Cover

Under Cover

Radiator Core Support

Fender SupportFront Cowl

Energy AbsorptionPipe

RR luggage space

RR luggage Partition

FR Dash

Door inner& impact beam

Hood Roof◆ Conventional car and CFRTP car

Vehi

cle w

eigh

t [kg

]

1500

1000

500

0Conventional Proposed

Aluminum

Others

CFRP

30%30%reductionreduction

Steel

The light‐weight CFRTP automotive model(parts replacement case)

In above calculation, anisotropy and integrated design are not considered

Flexural stiffness Torsional stiffness Weight

Isotropic 152 210 151kg

Anisotropic 200 286 151kg

Schematic diagram of the occurrence of industrial waste

Market50 – 70 %

Raw CF100 %

Industrial waste30 – 50 %

‐‐‐‐‐‐‐‐‐‐‐‐‐ waste at trimming ‐‐‐‐‐‐‐‐‐‐‐‐‐

‐‐ storage loss ‐‐

‐‐‐‐‐‐‐ quality assurance inspection ‐‐‐‐‐‐‐

‐‐‐‐‐‐‐‐ NG parts ‐‐‐‐‐‐‐‐

Schematic diagram of the occurrence of industrial waste

Market50 – 70 %

Raw CF100 %

Industrial waste30 – 50 %

‐‐‐‐‐‐‐‐‐‐‐‐‐ waste at trimming ‐‐‐‐‐‐‐‐‐‐‐‐‐

‐‐ storage loss ‐‐

‐‐‐‐‐‐‐ quality assurance inspection ‐‐‐‐‐‐‐

‐‐‐‐‐‐‐‐ NG parts ‐‐‐‐‐‐‐‐

Plate recycle

In‐houserepair

No storage

loss

Crushed recycleto high performance secondary member

Shop repair

< Monocoque body >Better structure for lightweight

panel88%

frame12%

panel57%

frame30%

casting13%

< Frame monocoque hybrid body >Better for safety and recyclability

Automotive Materials and Structures

Automobile parts are mostly composed of plates. Flexural properties are dominant in the case of automotive materials and structures.

Energy intensity of Parts production

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Repaired or Recycled CF/PP

Fresh CF/PP (Vf=20)

Fresh CF/PP (Vf=30)

Fresh CF/PP (Vf=40)

Recycled CF/EP with PP

Fresh CF/EP (Vf=40)

Fresh CF/EP (Vf=50)

Fresh CF/EP (Vf=60)

Recycled Steel

Fresh Steel

Energy intensity [MJ/kg]

assembly, molding steel or matrix resin productionCF production materials recoverly

Considering the 3√E/ρ,energy intensity are the same !

SustainableHyper

Japanese National Program to Develop CFRTP for Mass Produced Automobile

2008 – 2012fyTotal budget: 3.8 billion JPY (≒42 million US$)

1. CF/PP and CF/PA sheetssurface treated CF and modified thermoplasticscontinuous and discontinuous CF reinforced sheets

2. High cycle molding technologypress formingbladder molding

3. Jointing technology

4. Repair and recycling

Difference in adhesion between CFRTS and CFRTP

Heat Up

CFRTS: Bolted or adhesive joint ‐‐‐ weaker than base material

CFRTP: Welding joint ‐‐‐ the same or stronger than base

material

fiber tangles and fiber volume fraction becomes higher at the welded section !

Controlling toughness with fracture mechanism

The fracture mechanism of CFRTP can beductile in comparison to that of CFRTS.

CF/PP CF/EP

Buckling

Delaminating

Fiber Breaking

Compression Side

Compression Side

Difference between CFRTP and CFRTS verified by bending test results

Adviser

Development of Sustainable Hyper Composite Materials Technology (2008‐12)

Participants

Project LeaderProf. Jun TakahashiThe Univ. of Tokyo

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Specific bending stiffness ( )

Spec

ific

tens

ile s

tren

gth

(σf/ρ

)

CFRTS (Rapid Molding)

CFRTS (For airplanes)

Titanium

Aluminum

Magnesium

GFRP

Vf=0.5

Steel (780MPa)

Steel (440MPa)

Steel (270MPa)

Steel (1470MPa)

CFRTPVf=0.1

• TS: Thermosetting• TP: Thermoplastic• Vf: Fiber volume fraction

Specific Bending Stiffness and Tensile Strength

ρ/3 E

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0.0 0.1 0.2 0.3 0.4 0.5 0.6Fiber Volume Fraction

Wei

ght R

atio

of C

FRP

and

Stee

l Pan

el PPPAPCUP

Fiber Volume Fraction vs. Weight Reduction Ratio

Aluminum: 0.51

Magnesium: 0.38

Weight reduction is the same or betterInexpensiveImpregnation becomes easier

CF/EPCF/PPElastic strain range is not sufficient as a structural

member

Weight Reduction Ratio of CFRP and Steel Panel

Materials

FlexuralModulus

[GPa](E)

FlexuralStrength

[MPa](σ)

Density

[g/cc](ρ)

SpecificFlexuralStiffness(3√E/ρ)

SpecificFlexuralStrength（√σ/ρ）

Steel Panel 200 420 7.8 0.75(×1)

2.6(×1)

UD-CFRP(for Airplane) 138 1600 1.5 3.5

(×4.6)27

(×10)UD-CFRTP

(target) 115 1600 1.4 3.5(×4.6)

29(×11)

quasi-isotropicCFRP 50 700 1.5 2.5

(×3.3)18

(×6.7)quasi-isotropicCFRTP (target) 23 400 1.2 2.4

(×3.2)17

(×6.3)

Comparison of steel panel, CFRP and CFRTP

Displacement

steel panel Thermosetting CFRP○ weight is 1/3 of steel panel○ elastic strain range is 4 times

→ decrease the frequency of repair× fracture is brittle× repair and recycle is difficult

Developing CFRTP○ weight is 1/3 of steel panel○ elastic strain range is 4 times

→ decrease the frequency of repair○ fracture is ductile → safety○ repair and recycle is (maybe) easy

Displacement

E=23GPa, σ=400MPa・ 3√E/ρ is 3.2 times of steel・ √σ/ρ is 6.3 times of steel・elastic strain range is ±1.74%

steel panel

E=23GPa, σ=250MPa・ 3√E/ρ is 3.2 times of steel・ √σ/ρ is 5.0 times of steel・elastic strain range is ±1.09%

E=23GPa, σ=100MPa・ 3√E/ρ is 3.2 times of steel・ √σ/ρ is 3.2 times of steel・elastic strain range is ±0.43%

Comparison of the strength of CFRTP

If the fracture resistance is sufficient, strength of CFR(T)P isnot so severe criterion in case of automobile.

Therefore, CF produced from various precursors (not only PAN) can be used in automobiles.

Thank you for your kind attention.