Carbon Fiber Present
11
Application of Carbon Fiber for Large Structural Components Application of Carbon Fiber for Application of Carbon Fiber for Large Structural Components Large Structural Components
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Presentacion de Fibra de Carbon
Transcript of Carbon Fiber Present
Application of Carbon Fiber for Large Structural Components
Application of Carbon Fiber for Application of Carbon Fiber for Large Structural Components Large Structural Components
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Primary Goals•Allow thin panel fabrication with liquid molding•Provide increased stiffness to offset loss of thickness
•Develop full structural capability using multiple fibers
•Achieve Class A (truck) surface quality
Other Goals•Provide durability necessary to prevent reverse impact damage
•Process cycle times better than open molding and comparable to liquid molding into preforms
Application of Carbon Fiber for Large Structural Components
Application of Carbon Fiber for Large Application of Carbon Fiber for Large Structural ComponentsStructural Components
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AccomplishmentsAccomplishmentsAccomplishments
Class “A” finishesImproved impactThin walled RTM 2.5 mmOptimized filler loads for class “A”Mechanical Properties tests on various panel typesNew tooling systems for improved thermodynamic control New materials that provided very low resistance to flow and robust processing
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Where Does 20% Weight Savings Come From?
Where Does 20% Weight Savings Come Where Does 20% Weight Savings Come From?From?
Typical hood and fairing weights of 500-1000 lbsWeight savings of up to 50%Comparable material costsLower tooling cost compared to SMCAlternative manufacturing methods to SMC or wet moldingImproved impact properties
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Fiber SelectionFiber SelectionFiber Selection
Stiffness OffsetRequired carbon fiber to address h3 stiffness decreaseMaterials only needed in specific areas and orientationsCarbon necessary to meet local flat panel stiffness criteriaShape and form determine stiffness as much as panel t
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Resin System SelectionResin System SelectionResin System SelectionKey Criteria
Excellent neat resin impact propertiesCapability to bond to multiple fiber systemsCapability to liquid mold structures (not SRIM)Rapid process cycle times
Secondary criteriaLow costCompatible with fillers
? (+)-++
+/-
Liquid Molding
++ / +++--Polyesters
- / +++++Urethanes+ / +++++Blended PU/PE
- / ++?+/-Vinylesters- / --++Epoxies
Cost/FillersCycle timeAdhesionImpactResin Type
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Hybrid Fiber InteractionsHybrid Fiber InteractionsHybrid Fiber InteractionsProcessing
Injection/compression moldingCompatible binders required to hold materials in placeMolding pressures to 65 psiCycle times limited by flow as much as resin kinetics, 12 minutes achieved
Panel QualityHigh-fiber densities achievedExcellent adhesion to glass and carbon phasesFiber loft factors were key determinant in molding
Fiber48.12%Matrix49.93%Porosity1.88%
glass
carbon Su
rface
coat
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Mechanical Performance ResultsMechanical Performance ResultsMechanical Performance ResultsImpact Energy
Key determinant of panel durability (in-plant damage of thin panels)Excellent performance as compared to SMC (automotive grade hi-impact) and glass/preform technologyNo degradation seen with carbon fiber systems
Fatigue PerformanceMinimal loss of strength over testSamples ran over 7 million cycles with under 5% loss
00.5
11.5
22.5
3
SMC
Liquid/PreformHybrid/glassHybrid/Carbon
Impact Energy- first crack (J)
Typical Fatigue CurvesOver 80% loss with glass
Dramatic improvement infatigue of hybrid system
4-point Flexural Fatigue Testing235 Mpa Flexural Strength
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.00E
+00
5.00E
+05
1.00E
+06
1.50E
+06
2.00E
+06
2.50E
+06
3.00E
+06
3.50E
+06
4.00E
+06
4.50E
+06
5.00E
+06
Cycles
Perc
ent o
f Fle
xura
l Str
engt
h
Unfilled20041216_1_1200412161_2_3
Filled System
Filled System
Unfilled System
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Mechanical Performance Results - Cont’dMechanical Performance Results Mechanical Performance Results -- ContCont’’ddDesign Capability
Developed methods to design and model strength/stiffness of componentsExcellent correlation with test panelsNear full property translation for carbon and glass fractions with blended hybrid resins
Flexural Testing on Hybrid System
0
50
100
150
200
250
300
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
Strain (mm/mm)
Flex
ural
Str
ess
(MPa
)
20031215-1
Discontinuous CarbonComposite
Discontinuous CarbonHybrid Composite
Flexural stress results on hybrid composite with blended urethane resin system
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Lessons LearnedLessons LearnedLessons Learned
Key DevelopmentsThin walled RTM <2.5mm thicknessRTM polyurethane systemsLarge lightweight RTM tools
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ConclusionsConclusionsConclusions
Modeled properties and developed effective designs using discontinuous fibers with blended hybrid resinsExcellent adhesion is achieved with various fiber phasesResin systems significantly improve hybrid fiber compositesVery rapid cycle times for molding Use of carbon and glass fiber combinations with class A finishDeveloped and performed process trials with a new tooling system
