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TRANSCRIPT
LIGHTWEIGHTING VEHICLES USING
ADVANCED PLASTICS AND COMPOSITES
National Research Council
Committee on Fuel Economy of Light-Duty Vehicles, Phase 2
Exploring Options for Lighter-Weight Vehicles
February 13, 2012 – Ann Arbor, MI
Presentation Highlights • American Chemistry Council Plastics Division Automotive Team
• Life Cycle Analyses (LCA) of Polymers in Automotive Applications
o Keith Christman, Managing Director ACC Plastics Division
• Opportunities for Lightweighting Vehicles Using Advanced Plastics and
Composites – the Safety Perspective
o Dr. Tom Hollowell – ACC Technical Consultant
• Predictive Engineering of Plastics and Composites in Automotive
Applications
o George Racine, Manager Strategic Market Research ExxonMobil Chemical
and ACC PD Automotive Market Team Chairman
• Challenges & Possible Solutions
• Closing Remarks, Questions & Answers 2
American Chemistry Council (ACC)
• The American Chemistry Council represents the leading companies
engaged in the business of chemistry
• ACC members apply the science of chemistry to make innovative
products/services that make people’s lives better, healthier and safer
• ACC is committed to improved environmental, health and safety
performance through Responsible Care®, common sense advocacy
designed to address major public policy issues, and health and
environmental research and product testing
3
ExxonMobil Chemical – George Racine, Chairman
Bayer MaterialScience – Jose Chirino
BASF Corporation – Marianne Morgan
Braskem America – Terry Glass
Chevron Phillips Chemical Company – Sandra McClelland
Dow Automotive – John Lemanski
DuPont Engineering Polymers – Mike R. Day
Lanxess Corporation – Jens Fischer
LyondellBasell – Jane Horal
SABIC – V. Umamaheswaran
Styron, LLC – Jim Otis
Solvay Advanced Polymers, LLC – Bill Gaines
TOTAL Petrochemicals USA, Inc. – Jack A. Cahn
The Vinyl Institute
ACC Plastics Division Automotive Team Members
4
DEMAND
• Plastics use in autos growing
significantly
o Plastics and composites
grew 15% from 2010 to
2011; 119% since 2001
o Unprecedented fuel
economy requirements
driving demand faster and
farther
• Today’s autos ≈10% plastics
by weight but ≈50% plastics
by volume
Role of Plastics & Composites in
Automotive
5
SAFETY
• Interior cushioning
• Instrument panels
• Air bags
• Seat belts
• Tires
• Crumple zones
• Foam filled pillars
• Bumpers
• Safety glass
• Shatter resistant windows
• Pedestrian safety: cushioning body panels
http://plasticscar.blogspot.com/2012/04/inflatable-seatbelts.html
http://www.plastics-car.com/plasticfoams
Role of Plastics & Composites in
Automotive
6
BOLD DESIGN
• Driving innovation
• Aerodynamic efficiency
• Ease of shaping
• Integration of components
• Consolidation of parts
• Reduced assembly times
• Interior of many cars is nearly
all plastics
Role of Plastics & Composites in
Automotive
7
Role of Plastics & Composites in Automotive
FUEL & ENERGY EFFICIENCY
• Saves energy & reduces greenhouse gas emissions
• Weight reduction and improved fuel efficiency
• Average 22.9 MPG for model 2011 vehicles
o Would be as low as 16.2 MPG
• Life Cycle Benefits & Reduced energy consumption
o Would be 14.4%-28.2% above current levels
Chemistry in Light Vehicles, Economics & Statistics Department, American Chemistry Council, August 2012, http://www.plastics-car.com/lightvehiclereport
8
Life Cycle Analyses (LCA) of Polymers in Automotive Applications
• Comparative Cradle-to-Grave LCAs by PE INTERNATIONAL
o Ford Taurus Front End Bolster
o Chevrolet Trailblazer/GMC Automotive Assist Step
• Reducing part weight/fuel use with plastics & composites
• Dramatic reductions in energy use and CO2 emissions
• ISO 14040/44 compliant, critically reviewed
9
Life Cycle Analyses (LCA) of Polymers in Automotive Applications
Life Cycle – Chevrolet
Trailblazer/GMC Plastic Running
Board
• 51% lighter weight
• Saves fuel--equivalent to saving 2.7
million gallons of gasoline
• Consolidates parts
• Reduces assembly times
• Meets performance requirements
• Less global warming potential
http://plastics.americanchemistry.com/Education-
Resources/Publications/Life-Cycle-Assessment-of-
Polymers-in-an-Automotive-Assist-Step.pdf
10
Life Cycle Analyses (LCA) of Polymers in Automotive Applications
Life Cycle – Ford Taurus Front
End Bolster
• 46% lighter weight
• Saves fuel--equivalent to saving
770,000 gallons of gasoline
• Consolidates parts
• Reduces assembly times
• Meets performance
requirements
• Less global warming potential
http://plastics.americanchemistry.com/Education-
Resources/Publications/Life-Cycle-Assessment-of-
Polymers-in-an-Automotive-Assist-Step.pdf
11
February 13, 2013
OPPORTUNITIES FOR LIGHTWEIGHTING VEHICLES USING ADVANCED PLASTICS AND COMPOSITES – THE SAFETY PERSPECTIVE TOM HOLLOWELL, PH.D.
Biography Sketch, William Thomas (Tom) Hollowell, Ph.D. • President WTH Consulting, LLC
o Among clients are the American Chemistry Council, the European
Commission, the Japanese National Traffic Safety and Environment
Laboratory, Nagoya University in Japan, and the SAE
o Co-authored NHTSA Silverado Lightweighting Study
o He serves as an associate editor for the Journal for Traffic Injury Prevention
and is active in the SAE
• Retired from the National Highway Traffic Safety Administration
o Served as the Director of the Office of Applied Vehicle Safety Research
• Internationally recognized expert in vehicle crash safety
• Published over 50 technical papers on vehicle crashworthiness crash
modeling, crash testing, accident statistics, and impact biomechanics
• Elected an Society of Automotive Engineering (SAE) Fellow in Jan. 2005
13
Outline of Presentation
• Background
• NHTSA Safety Roadmap
o Strategic Priorities for 2020
o Challenges
• PCIV Project
o Participants
o Methodology
o Lightweighting of Components
o Safety Performance
Component Level Performance
Full System Performance (NCAP Frontal Test)
• Summary, Recommended Future Activities, and Closing Remarks
14
Background
• Recent studies show that good designs for LW can provide equiv.
safety
• In November 2007, NHTSA published PCIV safety roadmap
• In October 2009, NHTSA initiated GWU study, “Investigate
Opportunities for Lightweighting Vehicles using Advanced Plastics
and Composites,” as part of implementing PCIV safety roadmap
• In December 2010, NHTSA initiated Electricore project, Mass
Reduction for Light Duty Vehicles for Model Years 2017-2025
• In February 2011, NHTSA hosted Workshop on Vehicle Mass-Size-
Safety (http://www.nhtsa.gov/Laws+&+Regulations/CAFE+-
+Fuel+Economy/NHTSA+Workshop+on+Vehicle+Mass-Size-Safety
• Numerous NHTSA rulemaking actions
15
Strategic Priorities from NHTSA’s PCIV Safety Roadmap
Strategic Priorities for 2020 Plastics and Composite Intensive Vehicles Safety Assurance
Material Selection Testing Crash Performance PCIV Integration
Near-term
2007 - 2010
Perform research and technology to
address "knowledge gaps" on
crash-safety performance of PC
materials
Standardize testing protocols for
composite materials
Characterize mechanical
behavior of plastic/composite
materials in safety applications
Establish comprehensive
Database for lightweighting
materials options
Refine predictive engineering
tools for Modeling and
Simulation of PCIV
components and system crash
performance
Mid-term
2010 - 2015
Modeling and Simulation to verify
and validate plastic/composite crash
safety structural, semi-structural
applications
Validate plastic/composite material
choices in safety applications
Prototype and test component
(doors panels, root, front and
back "crush boxes"
Verify and validate for baseline
PCIV design to evaluation
integrative safety system
performance
Devise and evaluate special
crash-protection needs for
older occupants
Long-term
2015 - 2020
Demonstrate integrated safety
performance for prototype PCIV to
enable commercial deployment
Industry crash-test and self-certify
PCIV safety
Identity and overcome PCIV
crash-compatibility problems
for all occupants
Demonstrate enhanced PCIV
safety performance for older
occupants (using advanced
dummies)
NHTSA verifies PCIVs
compliance with crash-safety
regulatory requirements
16
Challenges… • Manufacturing challenges: availability, cost, cycle time, bonding,
repairability, recycling, etc.
• Failure prediction of composites is not mature enough for mainstream design
o Energy absorption in composites is by failure in a macro and micro scale Matrix cracking, delamination, debonding, fiber breakage
Reverse rate sensitive
• Current programs rely heavily on modeling & simulation tools to predict performance
• Older ferrous materials (isotropic, homogeneous) in current vehicle designs are reasonably predictive up until failure
o Predicting failure requires extensive material level characterization and model must be sensitive to rate of loading and mesh size
Final report: See link “A Safety Roadmap for Future Plastics and Composite Intensive Vehicles”
http://www.nhtsa.gov/Research/Crashworthiness/Vehicle+Aggressivity+and+Fleet+Compatibility+Research?%20vgnextoid=aba9099b7ec87210VgnVCM10000066ca7898RCRD
Brighton et al., Strain rate effects on energy absorption of composite tubes
17
Research Project
• Primary objectives of this research
o Evaluate current state of modeling &
simulation tools for predicting impact
response of plastic and composite materials in
automotive structures
o Investigate lightweighting opportunities using
a vehicle finite element (FE) model
o Evaluate the impact on crashworthiness
NHTSA published study (December 2012),
“Investigate Opportunities for Lightweighting
Vehicles using Advanced Plastics and
Composites”
18
Participants
WTH CONSULTING, LLC
Plastics Division
19
Methodology
• Develop a lightweight vehicle finite element model
o Select a candidate vehicle
o Identify components for lightweighting in the candidate vehicle
o Substitute original steel material with plastics/composites Help from ACC PD member companies and other available
resources
Materials available today or no later than the 2020 timeframe
Component level testing (simulation) to ensure equivalent performance
o Substitute steel ladder frame with composite frame Material tests (UDRI) to characterize candidate material (braided
carbon fiber-thermoset composite)
Evaluated under full system performance
• Compare the crash performance of two vehicles (baseline versus lightweighted vehicles)
20
Candidate Vehicle
2007 Chevy Silverado pickup truck
• Representative of popular vehicle type
• High potential for mass saving
• FE model of baseline vehicle available o NCAC FE model database
o Validated with the NHTSA’s frontal NCAP test
21
Lightweighting of Components
• Lightweighting methods
o Material substitution: Steel Plastics/composites or aluminum/magnesium
With or without design change (design changes by ACC PD member
companies)
Component change: Lighter engine, transmission, battery
Removal of component: spare tire & its carrier
• Resources
o Help from ACC PD member companies (BASF, SABIC, Bayer MaterialScience)
o Look into available resources (internet, technical papers, ……)
• Ladder frame
o Primary structural member in frontal impact
o Investigate applicability of composite material for main structural
component
o Material tests to characterize mechanical properties of a composite
22
Potential Weight Savings
Based on published literature from
USCAR ACC, 30% to 60% mass savings
is possible in vehicle structures
• Parts consolidation
o Many parts into one integrated
structure
• Vehicle weight reduction in one area
will have a cascading effect
o Smaller engines, brakes, power
assistance, suspension components
o Lower mass reduces fuel consumption
o Less momentum in impact and hence
less energy needs to be dissipated
23
Lightweighting Components
7 Groups – 30 Components Power train related
engine & transmission
engine oil pan
transmission oil pan
drive shaft & yokes
rear differential carrier
front-end module
battery
Suspension related
wheels (4)
front brake disks (2)
tires (4)
spare tire & carrier
leaf springs (2)
stabilizer links
Ladder frame structure
front bumper
rear bumper
transmission crossbeam
ladder frame
Occupant compartment structure
roof
A-pillar
B-pillar
Interiors
front seat
rear seat
IP retainer
Closures
front fenders
rear window
door beams
door modules
Truck bed structure
bed
tailgate
rear fenders 24
Lightweighted components
25
Occupant Compartment Structure: Roof
• Same structure, reinforcement is added around the boundary
• Steel material switched to a polycarbonate, and reinforcement material to a blend of semi-crystalline polyester (PBT or PET) and polycarbonate
• Thickness change: 0.949 mm 3.2 mm, 3.0 mm (reinforcement)
• 8.825 kg weight saving: 20.543 kg 11.718 kg
26
Occupant Compartment Structure: A- & B-Pillar Reinforcements
• Original model o A-pillar: no reinforcement, B-pillar: steel plate reinforcements
• New model o Composite inserts in the sections of A- & B-pillars (35% glass fiber
polyamide)
o 20% down-gauge of A- & B-pillars
o Designed by BASF
• Weight saving o 1.5 kg
27
Interiors: Seats & Instrument Panel
• Seats
o Seats are not modeled in vehicle FE model
Modeled by added masses
o Steel frame & foam Plastic frame & advanced foam
o Front seats: 20% mass reduction
10.0 kg weight saving: 50.5 kg 40.5 kg
o Rear seat: 20% mass reduction
8.9 kg weight saving: 44.6 kg 35.7 kg
• Instrument Panel (IP) Carrier
o IP is not modeled in vehicle FE model
Modeled by added masses
o Traditional IP New designed IP with lightweight material
o 4.0 kg weight saving
28
Closures: Front Fender
• Same structure
• Steel material is switched to modified polyphenylene ether and polyamide (PPE/PA) resin blend
• Thickness change: 0.076 mm 2.8 mm
• 3.534 kg weight saving: 7.916 kg 4.382 kg
29
Closures: Rear Window
• Same structure, reinforcement added around the boundary
• Glass material switched to a polycarbonate and reinforcement material to a blend of semi-crystalline polyester (PBT or PET) and polycarbonate
• Thickness change: 4.0 mm 4.0 mm, 4.0 mm (reinforcement)
• 2.729 kg weight saving: 6.502 kg 3.773 kg
30
Closures: Door Beams & Modules
Door Beams
• Original model
o Steel beams
• New model
o Composite beams: 35% glass reinforced
polyamide
o Designed by BASF
• Weight saving
o 4.92 kg, 55% less (8.97 kg 4.04 kg)
Door Modules
• Door modules not
modeled in vehicle FE
model o Modeled by added
masses
• Using a long glass fiber
reinforced
polypropylene [Sabic]
• 2.0 kg weight saving
31
Truck Bed Structure: Bed & Rear Fenders (Outer Panels)
Bed • Original model
o Steel material
• New model
o High density structural
reaction injection molding
(HD-SRIM) [Bayer
MaterialScience]
o No design change
• Weight saving
o 20.46 kg, 31% decrease (66.2
kg 45.74 kg)
Rear Fenders
• Original model o Steel material
• New model o Panel: PPE/PA blend
• Weight saving o 10.84 kg, 45% decrease (23.93
kg 13.09 kg)
32
Truck Bed Structure: Lift Gate
• Original 2 pieces changed to new 3 pieces
• Steel material switched to a blend of semi-crystalline polyester
(PBT or PET) and polycarbonate and to polypropylene reinforced
with long glass fibers
• 8.662 kg weight saving: 19.617 kg 10.955 kg
33
Power Train Related: Engine & Transmission
• 2007 Chevrolet Silverado Crew Pickup with 4.8L V8 Engine
o Engine & Transmission weight: about 400 kg
• V6 (4.3L) vs. V8 (4.8L)
o Weight difference of GVWR: 182 kg
o Weight difference of vehicle: 84 kg
• Extended Cab Pickup vs. Crew Pickup
o Weight difference of vehicle: 13 kg
• Assume mass saving of engine by switching V8 to V6 engine: about 100 kg
V6 V8
EX CR
GVWR (gross vehicle weight rating)
34
Power Train: Front-End Module
• Original 9 pieces changed to new 1 piece
• Steel material changed to a polypropylene reinforced with
long glass fibers
• 7.774 kg weight saving: 13.428 kg 5.654 kg
35
Power Train Related: Oil Pans & Battery
Battery
• Original model o Lead-acid battery
• New model o Lithium-ion battery
o No design change
• Weight saving o 10.76 kg, 60% decrease
(17.39 kg 7.17 kg)
Oil Pans
• Original model
o Engine & Transmission oil pans:
Steel
• New model
o 35% glass reinforced polyamide
o Designed by BASF
• Weight saving
o 5.22 kg, 50% decrease (10.46 kg
5.24 kg)
36
Power Train Related: Drive Shaft & Yokes, Rear Differential Carrier
Drive Shaft & Yokes
• Original model
o Steel
• New model
o Composite
o No design change
• Weight saving
o 3.69 kg, 58% decrease (6.37 kg
2.69 kg)
Rear Differential Carrier
• Original model o Steel
• New model o Magnesium alloy
o No design change
• Weight saving o 8.8 kg, 25% decrease (35.19 kg
26.39 kg)
37
Suspension Related: Wheels & Front Brake Disks
Wheels
• Original model
o Steel
• New model
o Aluminum
• Weight saving
o 20.06 kg, 40% decrease
(50.16 kg 30.09 kg)
Front Brake Disks
• Original model o Steel
• New model o Carbon-ceramic composite
• Weight saving o 14.39 kg, 50% decrease
(28.77 kg 14.39 kg)
38
Suspension Related: Tires & Spare Tire with Carrier
Tires
• Original model
o Traditional tires
• New model
o Lightweight tires
• Weight saving
o 8.75 kg, 10% decrease (87.49
kg 78.74 kg)
Spare Tire with Carrier
• New model o Spare tire and its carrier are
removed
• Weight saving o 38.79 kg
39
Suspension Related: Leaf Springs & Steering Stabilizer Links
Leaf Springs • Original model
o Steel
• New model
o Composite
o No design change
• Weight saving
o 34.73 kg, 70% decrease
(49.62 kg 14.88 kg)
Steering Stabilizer Links
• Original model
o Steel
• New model
o 35% glass reinforced polyamide
o No design change
• Weight saving
o 0.14 kg, 40% decrease (0.36 kg
0.22 kg)
40
Ladder Frame Structure: Front Bumper
• Original 9 pieces changed to new 5 pieces
• Steel material changed to a blend of semi-crystalline polyester
(PBT or PET) and polycarbonate and to a polypropylene sheet
• 7.609 kg weight saving: 16.311 kg 8.702 kg
41
Ladder Frame Structure: Rear Bumper
• Original 6 pieces changed to new 3 pieces
• Steel material changed to a blend of semi-crystalline polyester (PBT or PET) and polycarbonate and plastic
• 6.324 kg weight saving: 16.075 kg 9.751 kg
42
Ladder Frame Structure: Transmission Crossbeam
• Original model
o Steel
• New model
o Inner structure: 35% glass reinforced polyamide
o Outer cover: carbon continuous fiber reinforced thermoplastic (CFRT)
o Designed by BASF
• Weight saving
o 4.4 kg, 56% decrease (7.9 kg 3.5 kg)
43
Ladder Frame Structure: Ladder Frame
• Original
o Steel
o Weight: 231.6 kg
o Primary structural member in frontal impact
• New
o Braided carbon fiber-thermoset composite
o Material tests conducted by UDRI to obtain
numerical material parameters
o Same geometry, wall thickness doubled
• Weight savings
o 74.8 kg, 32 percent (231.6 kg 156.8 kg)
44
Weight Reduction Summary
Items
Old
weight
(kg)
New
weight
(kg)
Weight
saving
(%)
Weight saving (kg)
(using
plastics &
composites)
(using
other
materials)
(changing
or removing
components)
Occupant compartment structure
Roof 20.54 11.72 43% 8.82
A-pillar 0.20
B-pillar 1.32
Interiors
front seat 50.50 40.50 20% 10.00
rear seat 44.56 35.66 20% 8.90
IP retainer 4.10
Closures
front fenders 7.92 4.38 45% 3.53
rear window 6.50 3.77 42% 2.73
door beams 8.97 4.04 55% 4.92
door modules 2.00
Truck bed structure
bed 66.20 45.74 31% 20.46
tailgate 19.62 10.96 44% 8.66
rear fenders 23.93 13.09 45% 10.84 45
Weight Reduction Summary (Cont’d)
Items
Old
weight
(kg)
New
weight
(kg)
Weight
saving
(%)
Weight saving (kg)
(using
plastics &
composites)
(using
other
materials)
(changing
or removing
components)
Power train related
engine & transmission 100.00
engine oil pan 7.54 3.72 51% 3.82
transmission oil pan 2.92 1.52 49% 1.43
drive shaft & yokes 6.37 2.69 58% 3.69
rear differential carrier 35.19 26.39 25% 8.80
front-end module 13.43 5.65 58% 7.77
battery 17.93 7.17 60% 10.76
Suspension related
wheels (4) 50.16 30.09 40% 20.06
front brake disks (2) 28.77 14.39 50% 14.39
tires (4) 87.49 78.74 10% 8.75
spare tire & carrier 38.79 0.00 100% 38.79
leaf springs (2) 49.62 14.88 70% 34.73
stabilizer links 0.36 0.22 40% 0.14
Ladder frame structure
front bumper 16.31 8.70 47% 7.61
rear bumper 16.07 9.75 39% 6.32
transmission crossbeam 7.90 3.50 56% 4.40
ladder frame 231.60 156.80 32% 74.80
Vehicle 2307.00 1874.24 19%
sub-total saving 254.35 28.86 149.55
total saving 432.76
46
Component Level Testing
• Purpose
o To check the crash performance of new components
o To check numerical stability and robustness of FE models of new
components
• Conduct some dynamic impact tests
o Flat rigid wall impact test
o Pole (10 inches) impact test
o Crush test (Roof)
o Others
• Velocity change can see reduced vehicle mass effect
o 35mph 30mph : 14.3% reduced momentum
o 2307 kg 1977 kg : 14.3% vehicle mass reduction
• For any new component not a load-carrying part, component tests
are not conducted 47
Occupant Compartment Structure: A- & B-Pillar Reinforcements
Component tests
• Roof compression test
o Quasi-static
o More buckling resistance of new model
o Comparable crash performance
• B-pillar bending test
o Quasi-static
o Comparable crash performance
48
Front Fender – Component Level Test
• Rigid wall impact test with speed of 35 mph
• Max. displacement of vehicle: 1051.8 mm (orig), 1115.0 mm (new)
49
Lift Gate – Component Level Test
• Pole impact test with speed of 35 mph
• Max. displacement of vehicle: 384.7 mm(orig), 399.8 mm(new)
50
Front-End Module – Component Level Test
• Pole impact test at speed of 35 mph
• Max. displacement of vehicle: 1442.9 mm (orig), 1462.2 mm (new)
51
Front Bumper – Component Level Test I
• Rigid wall impact test with speeds of 35 mph and 30 mph
• Max. displacement of vehicle
o 125.0 mm(orig, 35mph), 142.2 mm(new, 35mph), 122.5 (new, 30mph)
52
Front Bumper – Component Level Test II
• Pole impact test with speeds of 35 mph and 30 mph
• Max. displacement of vehicle o 379.0 mm(org, 35mph), 452.8 mm(new, 35mph), 382.2 (new, 30mph)
53
Rear Bumper – Component Level Test I
• Rigid wall impact test with speeds of 35 mph and 30 mph
• Max. displacement of vehicle
o 164.0 mm(org, 35mph), 181.4 mm(new, 35mph), 137.7 (new, 30mph)
54
Rear Bumper – Component Level Test II
• Pole impact test with speeds of 35 mph and 30 mph
• Max. displacement of vehicle o 304.7 mm(org, 35mph), 482.4 mm(new, 35mph), 399.4 (new, 30mph)
55
Full System Performance: NCAP Frontal Test
56
Frontal NCAP Performance: Lightweighted Vehicle
• 5 Lightweight vehicle configurations analyzed o To observe the crash performance of composite
ladder frame in frontal NCAP simulations
57
Frontal NCAP Test Results - Acceleration
• New2 – close to Original
• New2 & New4 – high peak at late time
• New3 & New5 – high peak at early time
58
Summary
• Overall weight reduction of 19 percent achieved
• Equivalent performance in frontal NCAP test (for composite ladder frame with rail walls with twice the thickness but 32%-56% less weight of the steel ladder frame)
• Material substitutions were based on what American Chemistry Council’s Plastics Division deemed available today or would be available no later than 2020
• Weight reduction largely achieved by simple material substitution and component redesign (i.e., not a “clean sheet” redesign of vehicle)
• Limitations of study: Costs, cycle time, bonding/joining techniques, repairability, recyclability, etc. not directly addressed
• Final Report (DOT HS-811692) available December 2012 at: http://www.nhtsa.gov/DOT/NHTSA/NVS/Crashworthiness/Plastics/811692.pdf
59
Future Recommended Activities to Solve Challenges
• Apply lessons learned from Chevrolet Silverado and Honda Accord
projects to other vehicles and validate results
• Create material characterizations of plastics and composites for
safety applications
• Develop comprehensive database for materials use in LS-Dyna
• Validate modeling efforts for components where plastics and
composites were used in material substitution
60
Closing Remarks
It is possible to lightweight vehicles, using advanced plastic
and composite materials, and provide equivalent safety
• Identified needs:
o Data to change prevailing attitudes
o Demonstration programs to demonstrate efficacy
o Improved education
o Improved predictive engineering
61
February 13, 2013
Predictive Engineering of Plastics and Composites in Automotive Applications
GEORGE RACINE, MANAGER STRATEGIC MARKET RESEARCH EXXONMOBIL CHEMICAL AND ACC PD AUTOMOTIVE MARKET TEAM CHAIRMAN
Outline of Predictive Engineering Presentation
• Predictive Engineering Overview
o Definition, Governance/Management, Goal, Importance
o State of the Art
o Short Fiber Thermoplastics & Long Fiber Thermoplastics
injection molded composites
• ACC Role
• ACC Funded Research
• New Research for 2013
63
Predictive Engineering
• DEFINITION: Use of finite element analyses with constitutive and
failure models to accurately simulate the mechanical performance
of plastic and composite components and systems
• GOVERNANCE / MANAGEMENT: Funded by ACC under direction of
predictive engineering technical consultant, technical support and
expertise provided by ACC PD Auto Market Team members
• GOAL: Advance the state of the art in predictive engineering and
modeling for automotive plastics, especially in structural and
safety related applications
• IMPORTANCE: *Critical for continued uptake of plastics and
polymer composites into automotive applications
*Source: Frost and Sullivan Automotive Light-Weighting Consortium final report-
October 10, 2011 64
Predictive Engineering State of the Art
SHORT FIBER
LONG FIBER
CONTINUOUS
FIBER
IMPROVING
Simulation
Performance
Source: ACC, WYGO Plastics Consulting analysis 65
• Short-Fiber Thermoplastics (SFT) :
• The most common injection-molded composite
• Glass (or carbon) fibers
• Polypropylene, nylon are common matrices
• Add fibers to any matrix to gain stiffness, reduce creep
Lfiber = 0.2-0.4 mm Lfiber = 10-13 mm
Short and Long Fiber Thermoplastics
Injection-Molded Composites
• Long-Fiber Thermoplastics
(LFT):
• Pultruded pellets give long
(initial) fiber length
• Glass or carbon fibers
• Polypropylene, nylon are
common matrices
• Better properties than SFTs;
easier processing than
continuous-fiber composites 66
ACC Predictive Engineering Role
Facilitate development of predictive engineering
tools for plastics and composites:
Provide communication and coordination between industry, government and academia
Help to define specific areas for ongoing research in materials, processing and properties
Help provide support to university or government labs efforts to undertake key research
67
ACC Predictive Engineering
• Research is designed to fill critical data gaps that will:
o Give auto manufacturers the ability to use finite element
analyses (with constitutive and failure models)
o Accurately simulate the mechanical performance of plastic
and composite components and systems
• This work is delivering solid, credible data to give tier
suppliers and OEMs:
o Confidence needed to specify plastics as a means of meeting
safety and lightweighting goals
o Meet & support increased demand for plastics and composites
in automotive
68
ACC Predictive Engineering
• In 2012, ten years of research conducted in ACC partnership
with federal agencies, and validated by National Labs, was
made available for first time in engineering software for long
glass fiber reinforced plastics
• These advancements in long glass fiber modeling were
presented at the SAE World Congress, the Automotive
Composites Conference & Exhibition, and the Detroit Global
Automotive Lightweight Materials Conference
• ACC continues to support research on LGF at various
universities and ORNL and is participating in Carbon Fiber
(CF) research being funded by the Department of Energy
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ACC Funded Predictive Engineering Research
• Oak Ridge National Lab
• University of Illinois
• Virginia Tech
• University of Dayton Research Institute
• Michigan State University
• Axel Products Testing Laboratory
• Mississippi State University
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Oak Ridge National Lab (ORNL) “Develop Process Models, Characterize Fiber Length & Define Fiber Orientation Distributions”
Principal Investigator: Oak Ridge National Lab, Vlastimil Kunc
Department of Energy Funded Objectives (completed):
• Process models were developed to provide Long Fiber Thermoplastics Microstructure
• Micromechanics models were developed to predict Long Fiber Thermoplastics Mechanical Performance
ACC Funded Objectives (completed):
• Characterized fiber length distributions(FLD) in plaques from DOE funded molding trial for model research at the U. of Illinois
• Defined fiber orientation distributions(FOD) along with FLDs for UDRI specimen locations for high strain rate tensile tests
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University of Illinois “Long Fiber Length Attrition in a Molded Part”
Principal Investigator: U. of Illinois, Professor Chuck Tucker
Department of Energy Funded Objectives (completed):
• Developed Long Fiber Length Attrition model for molded
part structure and preliminary results were good
ACC Funded Objectives (completed):
• Simplify / transformed the model to speed up computation
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ORNL & University of Illinois Work Resulted in: A Proper Orthogonal Decomposition (POD) model being developed
• In 2012 the POD Model was further developed using Fiber
Length Distribution data from recently molded Long Glass
Fiber plaques
• Fiber Length Distribution data used from ORNL measurements
• Model to validate longer flow path (18”) than earlier
calculations and possibly longer fiber lengths
• Complements research at Virginia Tech
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Virginia Tech “Modeling Fiber Breakage in the Injection Molding Machine”
Principal Investigator: Virginia Tech, Professor Don Baird
ACC Funded Objectives (ongoing):
• Develop mathematical model
• Utilize dimensionalized parameters to develop an
empirical model
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University of Dayton Research Institute (UDRI) “Specimen Optimization for High Rate Tensile Testing of Long Fiber Filled Plastics” Principal Investigators: UDRI, Susan Hill and Peter Phillips
ACC Funded Objectives (completed):
• Additional testing of Long Fiber in using newly molded
plaques
• Characterize microstructure of plaques
• Goal is longer fiber lengths and data
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Michigan State University “Modeling Injection Molded Long Fiber Thermoplastic Composites” Principal Investigator: Michigan State University, Professor Xinran Xiao
ACC Funded Objectives (completed):
• Develop a FEA model for high rate impact prediction of Long Fiber Thermoplastics (LFT) components
• 2011: Examined feasibility of modeling in-plane and out-of-plane elastic behavior using a simple laminate approach
• 2012: Utilized a more detailed model with Moldflow or Moldex process software coupled to Digimat composite modeling software
• Provide the FEA material model for LS-Dyna predictions of driven dart impact
Note: Plaques previously characterized by ORNL
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Axel Products, Inc.: Physical Testing Services “Measuring Accelerated Fatigue Crack Growth” Principal Investigator: Kurt Miller
ACC Funded Objectives (ongoing):
• Establish a commercial source to obtain fatigue design data for short glass fiber (SGF) reinforced plastics components
o Utilizing Standard Plaque Inc. as plaque molder
o S-N data generated using ISO tensile bars for flow and cross-flow orientations
• Validate an accelerated method to obtain fatigue design data for reinforced plastics
o Fracture Mechanics theory utilized in ACC Workshops being followed
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Measuring Accelerated* Fatigue Crack Growth TEST SET UP AT AXEL PRODUCTS INC.
*TEST TIME OF HOURS VS. MONTHS 78
Mississippi State University/Center for Advanced Vehicle Systems “Modeling Driven Dart Impact and Failure Prediction” Principal Researchers: Dr. Jean-Luc Bouvard and Professor Mark Horstemeyer
ACC Funded Objectives (completed):
• Phase III-Modeling Driven Dart Impact of Unreinforced Polypropylene Homopolymer and Copolymer – Also Focus on Failure Prediction
• All data (PC,PP,co-PP) and the detailed Internal State Variable Model being put on a website
• Website “User Manual” written
• Website has link to national site: TMS (the Minerals, Metals, and Materials Society 79
New Research 2013: Process Model & Mechanical Performance Validation
ACC Funded Objectives:
• Work with Oak Ridge National Lab to Form an Industry,
Academia and Government Laboratory Research Team
• Validate recently developed “Process Model” and
“Mechanical Performance Predictive Models” for Injection
Molded Long Glass Fiber (LGF) for a Part having a 3-
Dimensional Geometry
Department of Energy Funded Objectives:
• Awarded two grants for Long Carbon Fiber, Oak Ridge National Lab and Pacific Northwest National Lab
• Develop and Validate “Process Model” and “Mechanical Performance Predictive Models” for carbon fiber (CF) for a Part having a 3-Dimensional Geometry
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Process Model & Mechanical Performance Validation for LGF & CF
Outcome:
A Revolution in Structural Parts Creation
• Software “interfaces” created to enable easier future
validations
• Pathway for “Remolding” of parts created
• Other companies can validate their software using ACC
generated database – ORNL plans to create website for all data
in 2014
• Provides 3D Part Validation that OEMs Require
• Gives OEMs Ability to Design Parts Virtually
• Provides OEMs Equal Validation Confidence as Metals
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Predictive Engineering Closing Summary
• Advances in predictive engineering of reinforced plastics
have significantly increased in recent years
• Conducting case studies of actual components (3-D Parts)
and systems is a very important and needed next step
• Implementing more testing and test standards for data
suitable to feed FEA models is an ongoing effort
• The American Chemistry Council Plastics Division will
continue to facilitate the development of predictive
engineering tools through coordination and support of
industry, government and academia activity
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Overall PCIV Challenges & Possible Solutions
ACC’s Plastics in Automotive Markets Technology Roadmap
• Currently undergoing an update from 2009, release in 2014
• Drives long term strategy, identifies challenges/possible solutions:
o Repairability and joining for all lightweight materials
Multi-material education/excellence centers can help solve
Unlike other lightweight materials, plastics and composites are corrosion,
scratch and dent resistant
Self-repairing plastics & composites technologically feasible, within reach
o Infrastructure for manufacturing – cost of re-tooling, etc.
Multi-material education/excellence centers can help solve
Demonstration projects can show the industry how to overcome
o Material cost (carbon fiber) for large scale use
As demand increases with greater application use, cost will level
DOE and industry are partnering on cost reduction projects
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Closing Remarks & Questions
• Plastics and Composites in automotive applications will
continue to rise
o Pace will be quickened by manufacturers’ need to reach
increased fuel economy standards
o Solutions to challenges can be provided to the industry quicker
with more research dollars
• Plastics and Composite materials are exceptionally light with
superior strength and stiffness
o Protects Formula 1 Drivers, no deaths since 1994
Traditional metal monocoque replaced with carbon fiber, increasing
protection upon impact*
o Mass production now possible – 2014 Corvette Stingray
* http://www.formula1.com/inside_f1/safety/a_history_of_safety_in_formula_one/7426.html
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For More Information
Gina Oliver
Senior Director, Automotive Plastics
ACC Plastics Division
Automotive Center
1800 Crooks Road
Troy, MI 48084-5311
www.Plastics-Car.com
Keith Christman
Managing Director, Plastic Markets
ACC Plastics Division
700 2nd Street, NE
Washington, D.C. 20002