Hybrid Fiber-Reinforced Composites with Innegra™ S for...
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Hybrid Fiber-Reinforced Composites with Innegra™ S for Improved Impact Resistance and Safety Elizabeth Cates, Ph.D. Innegra Technologies
Transcript of Hybrid Fiber-Reinforced Composites with Innegra™ S for...
Hybrid Fiber-Reinforced Composites with Innegra™ S
for Improved Impact Resistance and Safety
Elizabeth Cates, Ph.D.Innegra Technologies
Competing Demands
High Strength Light Weight True costs?
– Raw materials – Processing– Total Cost of Ownership
Safety behavior different, less predictable
WeightCost
StrengthSafety
Fiber-Reinforced Composites
Failure Modes
FRP Composites Catastrophic Brittle
– Delamination / debonding– Fibrillation / Cracking /
Shear Failure– Fiber / Matrix fracture
Common Metals Progressive Plastic Deformation
– Ductile bending / wrinkling
Predictable / Programmable
Image Source: Yuen, S.C. and Nurick, G.N., “The Crushing Characteristics of Square Tubes With Blast-Induced Imperfections – Part I: Experiments”, J. Appl. Mech. 76(5), 051308, 2008
Image Source: Adams, D.F., “Testing the Crashworthiness of Composite Structures” High Performance Composites Sept. 2012, http://www.compositesworld.com/articles/testing-the-crashworthiness-of-composite-structures
Value of Hybridization
What composites do best!– Combine different materials with different properties to yield
something new Different types of hybridization
– Material– Structure– Process
Best case = synergistic interaction between components
High Modulus
FiberMatrix Resin
Hybridizing Technology
Hybrid FRP
Composite
Présentateur
Commentaires de présentation
Focus on Materials hybrids in this presentation
Hybridization Strategies
Ply-by-Ply Hybrid Fabric
Hybrid YarnHybrid Yarn
Fabric
Continuous Fiber Reinforcements– Ply-by-Ply: combining
plies of different fabrics– Hybrid Fabric: co-
weaving of different yarns into a single fabric
– Hybrid Yarn: blending of fibers at the yarn level, then forming into fabric
Hybrid Structure: combination of short fiber and continuous fiber reinforcement
ABOUT INNEGRA
What are Innegra Yarns?
Innegra S is an olefin-based high performance yarn used most often in conjunction with a high modulus fiber to increase toughness, durability, dampening, and in some cases, reduce weight.
Innegra H is a hybridized yarn containing Innegra and a high modulus fiber (carbon, glass, basalt, or p-aramid). These fibers are co-mingled at the filament level to combine the properties of both fibers in the same plane, resulting in increased performance.
FIBER COMPARISONS
Data for fibers other than Innegra are from manufacturer literature.
Fiber ComparisonsInnegra Aramid Basalt Carbon
(PAN)E-Glass S-Glass UHMWPE Quartz
Density g/cm³ 0.84 1.44 2.70 1.78 2.54 2.48 0.97 2.20
TensileStrength
MPa 667 2400 -3600
4840 5313 2600 4800 2200 - 3900 6000
Modulus GPa 15 60 - 120 89 292 72 85 65 - 132 72
Elongation at Break
% 9.5 2.2 – 4.4 3.2 1.8 4.0 5.5 3 - 4 3.0
UV Resistance
Very Good Poor Excellent Excellent Excellent Excellent Very Good Excellent
Solvent Resistance
Excellent Fair Excellent Very Good Very Good Very Good
Excellent Excellent
Moisture Absorption
% < 0.1 3.2 – 7.0 0.2 – 12.0 0 0.1 0.1 < 0.1 0
Max ProcessingTemp
°C 150Tm = 162 -
164
450Td = 427 -
500
980Tm =
3500Td = 3700
730Tm = 825
850Tm =
140Tm = 144 –
152
1070Tm =
Dielectric Constant (Dk)
2.2 3.4 2.0 – 3.2 conductive 6.2 5.2 2.25 3.7
DissipationFactor (Df)
0.0009 0.014-0.01 0.003 –0.015
conductive 0.003-0.004
0.002 0.0002 0.0001
Coefficientof Linear Thermal Expansion
ppm / K
-8.0 -4.0 to -4.9 8.0 -1.1 5.4 2.9 -12.0 0.54
Stress Strain Curve
Structural Effects
Rule-of-Mixtures Behavior– Tensile strength / modulus– Compressive strength /
modulus– Flex strength / modulus
Positive Deviation from Rule-of-Mixtures– Impact strength / energy
absorbed
Rule of Mixtures𝑋𝑋𝑐𝑐=𝐶𝐶𝑓𝑓𝑋𝑋𝑓𝑓𝑉𝑉𝑓𝑓 + 𝐶𝐶𝑚𝑚𝑋𝑋𝑚𝑚𝑉𝑉𝑚𝑚a𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑉𝑉𝑚𝑚 = 1 − 𝑉𝑉𝑓𝑓
For multiple fibers𝑋𝑋𝑐𝑐=𝐶𝐶𝑓𝑓𝑓𝑋𝑋𝑓𝑓𝑓𝑉𝑉𝑓𝑓𝑓 +𝐶𝐶𝑓𝑓𝑓𝑋𝑋𝑓𝑓𝑓𝑉𝑉𝑓𝑓𝑓 + 𝐶𝐶𝑚𝑚𝑋𝑋𝑚𝑚𝑉𝑉𝑚𝑚a𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑉𝑉𝑚𝑚 = 1 − 𝑉𝑉𝑓𝑓𝑓 − 𝑉𝑉𝑓𝑓𝑓
Primary fibers carry the load, secondary fibers provide increased impact resistance
Impact Energy Absorption - Carbon
0
200
400
600
800
1000
1200
1400
0
2
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3k carbon PW: 3-ply[0/45/90]
3k carbon PW: 4-ply[0/45]2S
3k carbon PW: 5-ply[0/45/90/45/0]
3k carbon PW: 6-ply[0/45/90]2S
HIC PW: 3-ply [0/45/90]
Fibe
r Are
al W
eigh
t (gs
m)
Impa
ct E
nerg
y (J
)
Impact Energy (J) Fiber Areal Weight (gsm)
100% higher impact at same basis weight
Hybrid Yarn100 % Carbon - Controls
INNEGRA HYBRID COMPOSITESEnd-Use Examples
Increase damage tolerance
Increase impact resistance
Reduce catastrophic failure
The Early Adopter – Formula One
“falling weight impact tests and the mallet tests both showedthe Innegra material to be equal to and generally superior to the Kevlar
equivalent. This was manifested both in terms of resistance to damage and minimizing the size and quantity of debris”. –G. Savage
from EVALUATION OF POLYPROPYLENE FIBER COMPOSITES FOR USE IN ACCIDENT DEBRIS RETENTION by Gary Savage, PhD
Carbon/Innegra F1 Wing
Carbon/Kevlar F1 Wing
Improved Impact Resistance
Application: Rear wing assemblies for automotive racing by Hurley Racing Products
Need: improved impact resistance in thin wall parts
Results: – Innegra fabric used in place
of honeycomb or foam core– Significantly improved impact
resistance– Removes need to add hard-
points for joints– Reduced failures where
structure bolts to support
http://www.hurleyracingproducts.com/
Présentateur
Commentaires de présentation
Top: rear wing assembly for sport prototype racer. The end plates are made with Carbon Fiber and 3800 Innegra from SATI. These make a very strong and light panel and remove the need for adding individual hard-points that would be required with a foam or honeycomb core. We have used the same construction for larger formula car end plates with good result. The rear tail cone serves as the wing mount and also as the rear crash attenuation device. The construction there is carbon fiber, Innegra, aluminum honeycomb, carbon fiber. We have been using this construction for front and rear attenuators and it has reduced the failures at the phenolic hard-points where the structure bolts to the chassis. Bottom right: Dual element wing made with carbon fiber and Innegra. There is no core material and also no spars - these are monocoque/stressed skin structures. Using Innegra rather than our traditional method using foam core has increased surface toughness without adding weight. These wing are subject to a lot of debris hits from rocks being thrown up by the rear tires. The surface toughness that comes from using Innegra rather than foam core has resulted in significantly less surface damage.
Improved Impact Resistance
12mm Carbon 400 J Impact 3k carbon twill / epoxy prepreg 40mm crack at surface Thermography NDE: crack
propagation into at least 4 layers
12mm Carbon – Innegra 400 J Impact 3k carbon PW + Innegra PW /
epoxy infusion 8mm crack at surface, dent Thermography NDE: No damage
observed from 2nd ply down
2nd Ply 3rd Ply + 2nd Ply 3rd Ply +
Interpretation of feature uncertain
Présentateur
Commentaires de présentation
Interpretation of feature in hybrid thermography is uncertain. Potential explanations could be starting point of delamination or could be locally compressed Innegra fiber.
Safer Failure Mode
Application: CFRP tubes for cycling, etc. by Lenzi Egisto
Need: safer failure mode Results:
• 100% carbon tubes “crashed” • Carbon-Innegra hybrid tubes
underwent greater distortion but the layers were still intact
• “It is essentially confirmed what we had set out to verify, namely, that the tube hybrid of carbon/Innegra has characteristics of elasticity, absorption of the deformation, clearly superior to the pipe in 100 % Carbon, which arrives at break in a brittle way.”
http://www.lenziegisto.it/en
Tube interior and exterior at peak force
Présentateur
Commentaires de présentation
“The use of pure carbon composite in cycling industry often found the frames and the handlebars produce microfractures, which can then lead to fragile and unexpected breaks of composite structure, with sometimes serious outcomes for users. It is essentially confirmed what we had set out to verify, namely, that the tube hybrid of carbon/Innegra has characteristics of elasticity, absorption of the deformation, clearly superior to the pipe in 100 % Carbon, which arrives at break in a brittle way.”
Improved Damage Tolerance
Application: Stock Car Racing Need: Lightweighting with
improved damage tolerance– Survive bump impacts during
race without losing functionality
Locations:– Air intake ducts
• Radiator (1)• Brakes (2)
Results: carbon/Innegra air intake scoops that resist collapsing upon impact and continue to function as designed
NASCAR figure used for illustration purposes only. No
endorsement should be inferred.
Présentateur
Commentaires de présentation
“We still use innegra in the front grill and the brake ducts. That enables it to resist failure at collisions. ” “When the front grille contacts another race car. The innegra helps it resist deformation and allows it to continue conducting its primary responsibility of allowing air flow to the radiator”
Post-Fracture Strength
Application: Whitewater kayak CFRP paddle shaft by Adventure Technology
Need: prevention of catastrophic failure on impact
Results:– Improved impact
resistance– Improved secondary
strength, reducing catastrophic failures in field
http://www.atpaddles.com/us/
Présentateur
Commentaires de présentation
Paddle shaft fractured in 3-point bend then taken out in the field for testing. The Duraweave shaft with Innegra retains about 75% - 80% of original strength and can continue to be used, while the 100% carbon shaft suffers catastrophic failure upon first stress and breaks in half. Pass around example shaft
New Vehicle Design
Clemson University Automotive Engineering Deep Orange Program– Team-based Masters’ Project– Sponsored by OEM – specific challenge – Student team responsible for market research, conception,
design, construction of prototype Deep Orange 5 – Urban Mobility for Generation Y & Z
– The idea: To create a better value proposition for young adults who have small amounts of disposable income and less interest in vehicle ownership, yet need a personal mobility solution that aligns with their complex lifestyle.
Clemson Deep Orange 5
Need: weight reduction, improved safety– Carbon fiber structures often
have a brittle failure - highly undesirable
– Old thinking: oversize laminates to avoid any plastic deformation. This often increases the weight and cost of the part.
– New thinking: DO5 used Innegra fibers to add some ductility to the laminates and was willing to take the tradeoff between stiffness and cost/weight.
Location: roof bows– Side pillar-less design– Roof bow & door required to
carry entire loads
Roof bow
DO5 – Roof Bow Laminate Design
Uni directional 0° (300 GSM)
Innegra HIC plain weave
Plain weave (300-600 GSM)
Uni directional 90° (300 GSM)Uni directional 45° (300 GSM)
Uni directional 90° (300 GSM)Uni directional 0° (300 GSM)Plain weave (300-600 GSM)
Uni directional 45° (300 GSM)Innegra HIC plain weave
Uni directional 0° (300 GSM)Plain weave (300-600 GSM)
Uni directional 90° (300 GSM)Uni directional 45° (300 GSM)
Uni directional 90° (300 GSM)Uni directional 0° (300 GSM)Plain weave (300-600 GSM)
Uni directional 45° (300 GSM)
Uni directional -45° (300 GSM)
Uni directional -45° (300 GSM)
Uni directional 0° (300 GSM)Uni directional 0° (300 GSM)
Laminate plan - original Laminate plan - with Innegra
12 Layers 10 Layers
Présentateur
Commentaires de présentation
HIC fabrics are thicker materials, so resulted in reduction in number of layers
DO5 – Structural Modeling
Innegra in Hybrid Composites
Larger window of design opportunities Advantages
– Place hybridizing material exactly where needed– Build in damage resistance, damage tolerance– Safer failure mode
Challenges– Designing with a material with very different
properties from standard reinforcements– Manufacturing process considerations
