Sandwich Composite Structure

Sandwich Composite StructureNanomaterials ProjectLaTecia Anderson-JacksonNano 704May 1, 2013Spring 2013

Table of ContentsNomenclature3Abstract4Introduction5Objective7Problem Formulation8Approach12Results/Discussion13References15Appendix16

Nomenclature

b = Beam widthD = Panel bending stiffnessEc= Compression modulus of coreEf= Modulus of elasticity of facing skinF = Maximum shear forceGC= Core shear modulus - in direction of applied loadGW= Core shear modulus - Transverse directionh = Distance between facing skin centerskb= Beam - bending deflection coefficientks= Beam - shear deflection coefficientl = Beam span (length)M = Maximum bending momentP = Applied loadS = Panel shear stiffnesstC= Thickness of coretf= Thickness of facing skinV = Panel parameter (used for simply supported plate) = Calculated deflectionf= Calculated facing skin stressC= Shear stress in core

Abstract

Sandwich composite structures are structures that have two stiff exterior face-sheets and a low to moderate stiffness core that are adhesively bounded together. They are structures that are widely used in aerospace, naval, and many other industries because they are light weight, cost effective, and flexural rigidity, for which, makes an ideal structure for designing panels in structural construction. This project consist of observing four designs of sandwich structures that consist of two materials for face sheets, Carbon Fiber-Reinforced Polymer and Glass Fiber-Reinforced Polymer, and two materials for the core, Aluminum Foam and Polyurethane Foam. To determine which combination of materials are optimal for designing a sandwich composite material, mechanical properties had to be gathered from a computer software, Edupak, and inputted in formulas in computer program, Excel. Optimization of a sandwich composite structure is determined by the thickness, deflection, and the price of the material. Based on the factors for optimization, two out of the four sandwich composite structure designs observed were optimized.

Introduction

Sandwich structures are widely used in aerospace, naval, and many other industries because in theory due to sandwich composites consisting of a low to moderate stiffness core which is connected with two stiff exterior face-sheets and is an ideal structure to use in designing panels in structural construction. The concept of using a sandwich structure is very suitable and pliable to the development of lightweight structures with high in-plane and flexural stiffness. Archimedes laid the foundation for sandwich composite structures in 230 BC by describing the laws of levers and a way to calculate density. However, the development of a sandwich beam began in 1652 when Wendelin Schildknecht, a marine engineer, whom reported, tested, and published about sandwich beam structures using curved wooden beam reinforcements for bridge construction. Currently, sandwich composite structures are developed into a structure resembling a honeycomb, for which is considered to as a honeycomb sandwich. Honeycomb sandwich provides many advantages in the structural engineering industry, such as, very low weight, high stiffness, cost efficient, and durability.Honeycomb sandwich panels consist of two thin face sheets and a lightweight thicker core. The composite used in a honeycomb sandwich panel has high shear stiffness to weight ratio and high tensile strength to weight ratio than an ideal I beam. Also, the sandwich enhances the flexural rigidity of the structure without adding extensive weight to the beam. The most common material used for the face sheets are composite laminates and metals. When determining what material to use for the face sheet, certain properties should be considered, such as, high stiffness (high flexural rigidity), high tensile and compressive strength, impact resistance, surface finish, environmental resistance, and wear resistance. The core materials could either be metallic or nonmetallic honeycombs, foams, balsa wood, trusses, and etc. When determining the core material the main property that should be taken into account is the density of the material because in order to achieve an effective structure the core material should provide less weight as possible to the total weight of the sandwich. The face sheet materials and core material are bonded together adhesively to provide bending and in plane loads from the face sheet and flexural stiffness and out-of-plane shear and compressive behavior from the core. The performance of sandwich panels depends on the core and the adhesive bonding of the face sheet to the core, along with the geometrical dimensions of the components. The most common issues with sandwich structures are the quality of the structure and the failure of mechanisms that are developed under various loading conditions. If proper materials are chosen for the face sheets and core, structures with high ratios of stiffness to weight can be achieved.This project will consist of designing a sandwich composite structure from specific materials that are provided from Edupak software that provides there mechanical properties, production methods, and pricing.

ObjectiveThe objective of this project is to provide an optimal design of a sandwich beam that meets the criteria of having high stiffness, lightweight, and low cost. The key components being observed are the estimated deflection, thickness of the core, thickness of the face sheet, and the price of the material to be used to develop a sandwich composite structure. Through observation the sandwich face sheets should be thick enough to withstand the chosen design stresses under design load given, 1060 lbs. In addition, the core should be thick enough and have adequate shear stiffness and strength so the probability of overall sandwich buckling, excessive deflection, and shear failure will not occur under load given. Lastly, the core should have high modulus of elasticity, and the sandwich should have flatwise tensile and compressive strength so the wrinkling of the two face sheets will not occur under load.

Problem FormulationIn order to achieve the goal of this project, calculations were conducted in excel for certain parameters in order to design a sandwich structure beam. Total thickness

tf is the face sheet thickness which considered as a free variabletc is thickness of the core which is considered as a free variable

Bending Stiffness

Ef is the modulus of elasticity of the face sheet and is given by Edupack for the two materials being evaluated, Glass Fiber Reinforced Polymer (GFRP) and Carbon-fiber Reinforced Polymer (CFRP).tf is the face sheet thickness which considered as free variableb is the beam width given as a fixed value or constraintShear Stiffness

b is the beam width given as a fixed value or constrainth is the distance to the center between the two face sheetsGc is the core shear modulus in direction to the applied load (Gc=Gw)Bending Deflection Coefficient

Kb is the bending deflection coefficient for central load simple supported beamShear Deflection Coefficient

Ks is the shear deflection coefficient for central load simple supported beam

Deflection

Kb is the bending deflection coefficient for central load simple supported beamP is the applied load that is given as a constraintl is the beam span (length)D is the panel bending stiffnessKs is the shear deflection coefficient for central load simple supported beamS is the panel shear stiffnessFor an optimizing design, both bending and shear components must be calculated.Maximum Bending Moment

P is the applied load that is given as a constraintl is the beam span (length)Face Stress

M is the maximum bending momenth is the distance to the center between the two face sheetstf is the face sheet thickness which considered as free variableb is the beam width given as a fixed value or constraintMaximum Shear Force

P is the applied load that is given as a constraintCore Stress

F is the maximum shear forceh is the distance to the center between the two face sheetsb is the beam width given as a fixed value or constraint

ApproachThe face sheets of a sandwich composite structure is a component that serves many purposes, depending upon the application, but in all cases the major applied loads are being carried. The stiffness, stability, formation, and strength of the face sheet are determined by the characteristics of the faces stabilized by the core. The two materials chosen as face sheets for this project are Glass Fiber-Reinforced Polymer and Carbon Fiber-Reinforced Polymer. These two materials are ideal to use as a face sheets because they have a very high strength to weight ratio, lightweight, and has a high quality of chemical and environment resistance. In order for a sandwich composite structure to perform satisfactorily, the core of the sandwich must have certain mechanical properties and thermal characteristics under conditions of use and still conform to weight limitations [2]. However, in this design the main focus for the core was the mechanical properties. The two materials chosen as the core are Polyurethane foam and Aluminum foam. These two foams are perfect materials to use for the core of the sandwich because they are flexible, provide thermal insulation, and low in density. Information on the materials mechanical properties, general properties, identification, durability, thermal properties, and etc. were obtained from composite software, Edupak (Appendix).

Figure 1. Depicting parameters needed to be calculated in excel to determine optimization of a beam [Ref. 4]

After obtaining general information on all four materials from Edupak, the formulas given from Hexcel composites packet were used in computer software, Excel. The parameters for an original I-Beam was given and the goal is to compare composite sandwich design to the parameters of the I-Beam concluding with better results. Some constraints for the composite design had to be met in order for this design to be successful and they are, total height not exceeding 15 inches, width being fix at either 12 inches or 36 inches, length fixed at 1200 inches, deflection () not exceeding 12 inches, and applied load fixed at 1060 lbs. These factors were put into excel to begin necessary calculations for the four composite designs. To determine which design is optimized the thickness of the face sheet and core had to be changed in increments of 0.1, which resulted in affecting the deflection, total price of materials, and total height of the structure. Observations has shown the best way to reduce deflection was to increase the core thickness, for which increased the skin separation and value of the total height. After studying results from changing core and face sheet thickness, a design could be chosen as the optimal materials to use for a composite sandwich structure. The objective was to observe the combination of which face sheet and core would produce the strongest sandwich structure at low cost, low deflection, and low weight.

Results/Discussion

Determining which materials are being optimized depends on many factors. Optimization of a sandwich composite structure is determined by the thickness of the material, deflection, and the price of the material. Observation has shown that width of the beam can affect these particular factors. When the beam is a width of 36 inches it increases the total price of the materials, deflection, and thickness of the material. Therefore, beam width of 12 inches was chosen to determine the best optimization of the sandwich composite structure. The materials that is optimal to use when determining low cost in relation to the weight of the material was Carbon Fiber-Reinforced Polymer with Aluminum Foam (Graph 1). Using core thickness of 9.48 inches and face sheet thickness of 0.3 inches gave a total thickness of 10.08 inches with a total price of $17,201.88, proving the material to be light weight and contributes to production cost savings. The best materials to use for optimization when determining deflection of the beam in correlation to thickness of the beam are Carbon Fiber-Reinforced Polymer with Polyurethane Foam (Graph 2). Using core thickness of 14.5 inches and face sheet thickness of 0.2 inches gave a total thickness of 14.9 inches with a deflection of 7.95, proving these two materials be light weight with a low deflection. Therefore, two out of the four sandwich composite structure designs observed were optimized.

Graph 1 Optimization was determined based on the material that was both lightweight and cost effective (Low Cost).

Graph 2 Optimization is determined by the material with the lowest deflection and lightweight.

References

[1] Ashby, M. F., and Daniel L. Schodek. Nanomaterials, Nanotechnologies and Design: An Introduction for Engineers and Architects. Amsterdam: Butterworth-Heinemann, 2009. Print. [2] "Core Specifications and Core Index." Core Specifications and Core Index. Department of Defense, n.d. Web. 03 May 2013. [3] Daniel, I. M., J. L. Abot, and K. A. Wang. TESTING AND ANALYSIS OF COMPOSITE SANDWICH BEAMS. Evanston: n.p., n.d. PDF. [4] HexWebTM HONEYCOMB SANDWICH DESIGN TECHNOLOGY. N.p.: Hexcel, n.d. PDF. [5] Johnson, Todd. "Understanding CFRPComposites." About.com Composites / Plastics. N.p., n.d. Web. 03 May 2013. [6] "Sandwich-structured Composite." Wikipedia. Wikimedia Foundation, 29 Mar. 2013. Web. 03 May 2013.

Appendix

Polyurethanefoam(rigid, closed cell, 0.6)IdentificationDesignationRigid polyurethane closed-cellfoam, 0.6 specific gravityTradenamesAirex, Last-A-Foam, NidaFoamGeneral PropertiesDensity 0.0202 - 0.0231 lb/in^3Price * 4.1 - 6.84 USD/lbComposition overviewComposition (summary)General formula (NH-R-NH-CO-O-R'-O-CO)n where R is from a diisocyanate, most commonly MDI or TDI, and R' is from a polyolBase PolymerPolymer class Thermoplastic : amorphousPolymer type PURPolymer type full name Polyurethane plasticFiller type UnfilledComposition detail (polymers and natural materials)Polymer 100 %Foam& honeycomb propertiesAnisotropy ratio * 1 - 1.5Relative density * 0.452 - 0.571Mechanical propertiesYoung's modulus * 0.0403 - 0.0965 10^6 psiCompressive modulus 0.075 - 0.0953 10^6 psiFlexural modulus * 0.124 - 0.164 10^6 psiShear modulus 0.0217 - 0.027 10^6 psiPoisson's ratio 0.333Shape factor 2.41Yield strength (elastic limit) * 0.545 - 0.989 ksiTensile strength 1.85 - 2.26 ksiCompressive strength 1.49 - 1.89 ksiFlexural strength (modulus of rupture) * 0.545 - 0.989 ksiShear strength 1.49 - 1.82 ksiThermal propertiesMaximum service temperature 275 - 351 FMinimum service temperature -337 - -301 FThermal conductivity * 0.0558 - 0.0734 BTU.ft/hr.ft^2.FSpecific heat capacity 0.351 - 0.388 BTU/lb.FThermal expansion coefficient 50 - 80 strain/FElectrical propertiesElectrical resistivity 9.35e18 - 6.27e19 ohm.cmDielectric constant (relative permittivity) 3.5 - 4.54Dissipation factor (dielectric loss tangent) 0.0626 - 0.0751Optical propertiesTransparency OpaqueAbsorption, permeabilityWater absorption @ 24 hrs 0.15 - 0.19 %Durability: flammabilityFlammability Highly flammableDurability: fluids and sunlightWater (fresh) ExcellentWater (salt) ExcellentWeak acids AcceptableStrong acids UnacceptableWeak alkalis AcceptableStrong alkalis Limited useOrganic solvents UnacceptableUV radiation (sunlight) FairOxidation at 500C UnacceptablePrimary material production: energy, CO2 and waterEmbodied energy, primary production * 4.64e4 - 5.12e4 BTU/lbCO2 footprint, primary production * 4.57 - 5.05 lb/lbWater usage * 7.75e3 - 8.58e3 in^3/lbMaterial processing: energyCoarse machining energy (per unit wt removed) * 283 - 313 BTU/lbFine machining energy (per unit wt removed) * 994 - 1.1e3 BTU/lbGrinding energy (per unit wt removed) * 1.78e3 - 1.97e3 BTU/lbMaterial processing: CO2 footprintCoarse machining CO2 (per unit wt removed) * 0.0494 - 0.0546 lb/lbFine machining CO2 (per unit wt removed) * 0.173 - 0.192 lb/lbGrinding CO2 (per unit wt removed) * 0.311 - 0.344 lb/lbMaterial recycling: energy, CO2 and recycle fractionRecycle FalseRecycle fraction in current supply 0.1 %Downcycle TrueCombust for energy recovery TrueHeat of combustion (net) 9.13e3 - 1.01e4 BTU/lbCombustion CO2 1.95 - 2.15 lb/lbLandfill TrueBiodegrade FalseA renewable resource? FalseNotesTypical usesCore material for lightweight sandwich panels and structures. Wind turbine nacelles, industrial containers, shelters and panels, automotive headliners, spoilers, seats, truck panels, side skirts. Boat decks, bulkheads, transoms, stringers.

Aluminum foam (0.5)IdentificationDesignationAluminum Foam (0.5)TradenamesAEROWEB 3003, AEROWEB 5052, DURACORE 5052, DURACORE 5056General PropertiesDensity 0.0173 - 0.0188 lb/in^3Price * 3.76 - 4.7 USD/lbComposition overviewComposition (summary)Al/12% SiBase Al (Aluminum)Composition detail (metals, ceramics and glasses)Al (aluminum) 88 %Si (silicon) 12 %Foam & honeycomb propertiesAnisotropy ratio * 1 - 1.1Cells/volume 246 - 1.64e4 /in^3Relative density 0.17 - 0.2Mechanical propertiesYoung's modulus 0.682 - 0.769 10^6 psiFlexural modulus 0.682 - 0.769 10^6 psiShear modulus * 0.254 - 0.29 10^6 psiBulk modulus * 0.682 - 0.769 10^6 psiPoisson's ratio * 0.28 - 0.3Shape factor 3Yield strength (elastic limit) * 0.725 - 1.45 ksiTensile strength * 2.18 - 2.9 ksiCompressive strength 0.725 - 1.45 ksiCompressive stress @ 25% strain 0.87 - 1.45 ksiCompressive stress @ 50% strain 2.18 - 2.9 ksiFlexural strength (modulus of rupture) 1.74 - 2.61 ksiElongation 60 - 70 % strainHardness - Vickers * 1 - 1.2 HVFatigue strength at 10^7 cycles * 0.58 - 1.31 ksiFatigue strength model (stress range) * 0.445 - 0.903 ksiParameters: Stress Ratio = 0, Number of Cycles = 1e7Fracture toughness * 1.64 - 2.09 ksi.in^0.5Mechanical loss coefficient (tan delta) 0.0018 - 0.0023Densification strain 0.6 - 0.7Thermal propertiesMelting point 1.02e3 - 1.14e3 FHeat deflection temperature 0.45MPa * 284 - 302 FHeat deflection temperature 1.8MPa * 266 - 284 FMaximum service temperature * 284 - 392 FMinimum service temperature -459 FThermal conductivity 4.04 - 8.09 BTU.ft/hr.ft^2.FSpecific heat capacity 0.217 - 0.229 BTU/lb.FThermal expansion coefficient 10.6 - 11.1 strain/FLatent heat of fusion 163 - 170 BTU/lbElectrical propertiesElectrical resistivity 31.6 - 34.7 ohm.cmGalvanic potential * -0.73 - -0.65 VOptical propertiesTransparency OpaqueAbsorption, permeabilityWater absorption @ 24 hrs 0.001 - 0.002 %Durability: flammabilityFlammability Non-flammableDurability: fluids and sunlightWater (fresh) ExcellentWater (salt) AcceptableWeak acids ExcellentStrong acids ExcellentWeak alkalis AcceptableStrong alkalis UnacceptableOrganic solvents ExcellentUV radiation (sunlight) ExcellentOxidation at 500C UnacceptablePrimary material production: energy, CO2 and waterEmbodied energy, primary production * 1.05e5 - 1.16e5 BTU/lbCO2 footprint, primary production * 14.4 - 15.9 lb/lbWater usage * 8.36e4 - 9.25e4 in^3/lbMaterial recycling: energy, CO2 and recycle fractionRecycle TrueEmbodied energy, recycling * 1.38e4 - 1.53e4 BTU/lbCO2 footprint, recycling * 2.52 - 2.79 lb/lbRecycle fraction in current supply 0.1 %Downcycle TrueCombust for energy recovery FalseLandfill TrueBiodegrade FalseA renewable resource? FalseNotesTypical usesEnergy absorption, Crash protection, Thermal insulation, Light weight structures, cores for sandwich structures, sound absorption, Electromagnetic shielding.Other notesAlso available as an open-celled foam.Reference sourcesData compiled from multiple sources. See links to the References table..

Glass/epoxy unidirectional compositeIdentificationDesignationEpoxy Unidirectional Composite (Glass Fiber)General PropertiesDensity 0.0578 - 0.0704 lb/in^3Price * 11.9 - 16.7 USD/lbComposition overviewComposition (summary)Epoxy + Glass FibersBase PolymerPolymer class Thermoset plasticPolymer type EPPolymer type full name Epoxy resin% filler (by weight) 30 - 60 %Filler type Glass fiberComposition detail (polymers and natural materials)Polymer 40 - 60 %Glass (fiber) 40 - 60 %Mechanical propertiesYoung's modulus 5.08 - 6.53 10^6 psiFlexural modulus 5.08 - 6.53 10^6 psiShear modulus * 2.1 - 2.7 10^6 psiBulk modulus * 2.92 - 3.76 10^6 psiPoisson's ratio 0.05 - 0.4Shape factor 6.8Yield strength (elastic limit) 43.5 - 160 ksiTensile strength 43.5 - 160 ksiCompressive strength 52.2 - 128 ksiFlexural strength (modulus of rupture) 43.5 - 131 ksiElongation 2 - 3 % strainHardness - Vickers * 33 - 58 HVFatigue strength at 10^7 cycles * 17.4 - 63.8 ksiFracture toughness 4.55 - 18.2 ksi.in^0.5Mechanical loss coefficient (tan delta) * 0.00278 - 0.00332Impact propertiesImpact strength, notched 23 C * 0.00177 - 0.11 BTU/in^2Thermal propertiesGlass temperature 212 - 356 FMaximum service temperature * 338 - 374 FMinimum service temperature * -189 - -99.4 FThermal conductivity 0.231 - 0.693 BTU.ft/hr.ft^2.FSpecific heat capacity * 0.227 - 0.251 BTU/lb.FThermal expansion coefficient 4.72 - 13.9 strain/FElectrical propertiesElectrical resistivity 1e20 - 1e21 ohm.cmDielectric constant (relative permittivity) 3.5 - 5Dielectric strength (dielectric breakdown) 300 - 500 V/milOptical propertiesTransparency TranslucentDurability: flammabilityFlammability Slow-burningDurability: fluids and sunlightWater (fresh) ExcellentWater (salt) ExcellentWeak acids AcceptableStrong acids UnacceptableWeak alkalis Limited useStrong alkalis ExcellentOrganic solvents Limited useUV radiation (sunlight) FairOxidation at 500C UnacceptablePrimary material production: energy, CO2 and waterEmbodied energy, primary production * 2.04e5 - 2.25e5 BTU/lbCO2 footprint, primary production * 25.3 - 28 lb/lbWater usage * 4.26e3 - 4.71e3 in^3/lbMaterial processing: energyAutoclave molding energy * 8.97e3 - 9.89e3 BTU/lbCompression molding energy * 1.43e3 - 1.58e3 BTU/lbFilament winding energy * 1.1e3 - 1.22e3 BTU/lbPultrusion energy * 1.27e3 - 1.4e3 BTU/lbMaterial processing: CO2 footprintAutoclave molding CO2 * 1.67 - 1.84 lb/lbCompression molding CO2 * 0.266 - 0.294 lb/lbFilament winding CO2 * 0.206 - 0.227 lb/lbPultrusion CO2 * 0.236 - 0.261 lb/lbMaterial recycling: energy, CO2 and recycle fractionRecycle FalseRecycle fraction in current supply 0.1 %Downcycle TrueCombust for energy recovery TrueHeat of combustion (net) * 5.16e3 - 5.42e3 BTU/lbCombustion CO2 * 0.968 - 1.02 lb/lbLandfill TrueBiodegrade FalseA renewable resource? FalseNotesTypical usesShip and boat hulls; body shells; automobile components; cladding and fittings in construction; chemical plant.

Epoxy/HS carbon fiber, UD composite, 0 laminaIdentificationDesignationHigh Strength Carbon Fiber/Epoxy Composite, 0 Unidirectional lamina.Material was produced from unidirectional tape prepreg, fiber volume fraction nominally 0.55 - 0.65. Autoclave cure at 115-180C, 6-7 bar.TradenamesCycom; Fiberdux; ScotchplyGeneral PropertiesDensity 0.056 - 0.0571 lb/in^3Price * 17.2 - 19.1 USD/lbComposition overviewComposition (summary)Epoxy + Carbon fiber reinforcementBase PolymerPolymer class Thermoset plasticPolymer type EPPolymer type full name Epoxy resin% filler (by weight) 65 - 70 %Filler type Carbon fiberComposition detail (polymers and natural materials)Polymer 30 - 35 %Carbon (fiber) 65 - 70 %Mechanical propertiesYoung's modulus 18.7 - 22.4 10^6 psiCompressive modulus 17.8 - 19 10^6 psiFlexural modulus 18.7 - 22.6 10^6 psiShear modulus 0.542 - 0.914 10^6 psiBulk modulus * 1.32 - 1.76 10^6 psiPoisson's ratio 0.32 - 0.34Shape factor 7Yield strength (elastic limit) 253 - 314 ksiTensile strength 253 - 314 ksiCompressive strength 204 - 245 ksiFlexural strength (modulus of rupture) 253 - 314 ksiElongation 1.2 - 1.4 % strainHardness - Vickers * 10.8 - 21.5 HVHardness - Rockwell M * 80 - 110Hardness - Rockwell R * 117 - 129Fatigue strength at 10^7 cycles * 139 - 204 ksiFracture toughness * 9.85 - 75.2 ksi.in^0.5Mechanical loss coefficient (tan delta) * 0.0014 - 0.0033Impact propertiesImpact strength, notched 23 C * 0.00177 - 0.0569 BTU/in^2Thermal propertiesGlass temperature 212 - 356 FHeat deflection temperature 0.45MPa * 534 - 639 FHeat deflection temperature 1.8MPa * 482 - 581 FMaximum service temperature * 284 - 428 FMinimum service temperature * -189 - -99.4 FThermal conductivity * 2.25 - 3.81 BTU.ft/hr.ft^2.FSpecific heat capacity * 0.215 - 0.248 BTU/lb.FThermal expansion coefficient * -0.244 - 0.0889 strain/FElectrical propertiesElectrical resistivity * 9.71e4 - 2.87e5 ohm.cmGalvanic potential 0.14 - 0.22 VOptical propertiesTransparency OpaqueAbsorption, permeabilityWater absorption @ 24 hrs * 0.036 - 0.0525 %Durability: flammabilityFlammability Slow-burningDurability: fluids and sunlightWater (fresh) ExcellentWater (salt) ExcellentWeak acids AcceptableStrong acids UnacceptableWeak alkalis Limited useStrong alkalis ExcellentOrganic solvents Limited useUV radiation (sunlight) GoodOxidation at 500C UnacceptablePrimary material production: energy, CO2 and waterEmbodied energy, primary production * 1.95e5 - 2.15e5 BTU/lbCO2 footprint, primary production * 32.9 - 36.4 lb/lbWater usage * 3.71e4 - 4.1e4 in^3/lbMaterial processing: energyAutoclave molding energy * 8.97e3 - 9.89e3 BTU/lbCompression molding energy * 1.43e3 - 1.58e3 BTU/lbFilament winding energy * 1.1e3 - 1.22e3 BTU/lbPultrusion energy * 1.27e3 - 1.4e3 BTU/lbMaterial processing: CO2 footprintAutoclave molding CO2 * 1.67 - 1.84 lb/lbCompression molding CO2 * 0.266 - 0.294 lb/lbFilament winding CO2 * 0.206 - 0.227 lb/lbPultrusion CO2 * 0.236 - 0.261 lb/lbMaterial recycling: energy, CO2 and recycle fractionRecycle FalseRecycle fraction in current supply 0.1 %Downcycle TrueCombust for energy recovery TrueHeat of combustion (net) * 1.34e4 - 1.41e4 BTU/lbCombustion CO2 * 3.17 - 3.33 lb/lbLandfill TrueBiodegrade FalseA renewable resource? FalseNotesTypical usesLightweight structural members in aerospace, ground transport and sporting goods; springs; pressure vessels.

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