Sandwich Composite Structure Nanomaterials Project LaTecia Anderson-Jackson Anderson-Jackson Nano 704 May 1, 2013 Spring 2013
Table of Contents
NOMENCLATURE
2
ABSTRACT
3
INTRODUCTION
4
OBJECTIVE
6
PROBLEM FORMULATION
7
APPROACH
11
RESULTS/DISCUSSION
13
REFERENCES
15
APPENDIX
16
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Table of Contents
NOMENCLATURE
2
ABSTRACT
3
INTRODUCTION
4
OBJECTIVE
6
PROBLEM FORMULATION
7
APPROACH
11
RESULTS/DISCUSSION
13
REFERENCES
15
APPENDIX
16
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Nomenclature b = Beam width D = Panel bending stiffness Ec= Compression modulus of core Ef = Modulus of elasticity of facing skin F = Maximum shear force GC= Core shear modulus - in direction of applied load GW= Core shear modulus - Transverse direction h = Distance between facing skin centers k b= Beam - bending deflection coefficient k s= Beam - shear deflection coefficient l = Beam span (length) M = Maximum bending moment P = Applied load S = Panel shear stiffness tC= Thickness of core tf = Thickness of facing skin V = Panel parameter (used for simply supported plate) δ = Calculated deflection σf = Calculated facing skin stress τC= Shear stress in core
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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.
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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
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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.
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Objective The 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.
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Problem Formulation In 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 variable tc 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 variable b is the beam width given as a fixed value or constraint Shear Stiffness 7|Page
b is the beam width given as a fixed value or constraint h is the distance to the center between the two face sheets Gc is the core shear modulus in direction to the applied load (Gc=Gw) Bending Deflection Coefficient
K b is the bending deflection coefficient for central load simple supported beam Shear Deflection Coefficient
K s is the shear deflection coefficient for central load simple supported beam
Deflection
K b is the bending deflection coefficient for central load simple supported beam P is the applied load that is given as a constraint l is the beam span (length)
D is the panel bending stiffness 8|Page
K s is the shear deflection coefficient for central load simple supported beam S is the panel shear stiffness For an optimizing design, both bending and shear components must be calculated. Maximum Bending Moment
P is the applied load that is given as a constraint l is the beam span (length)
Face Stress
M is the maximum bending moment h is the distance to the center between the two face sheets tf is the face sheet thickness which considered as free variable b is the beam width given as a fixed value or constraint Maximum Shear Force
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P is the applied load that is given as a constraint Core Stress
F is the maximum shear force h is the distance to the center between the two face sheets b is the beam width given as a fixed value or constraint
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Approach The 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 b y 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. Th ese 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]
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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 (δ) 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 m aterials, 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.
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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 t he 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.
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Price vs Total Thickness $45,000.00 $40,000.00 $35,000.00 $30,000.00 e$25,000.00 c i r P$20,000.00 $15,000.00 $10,000.00 $5,000.00 $0.00
GFRP with Aluminum Foam GFRP with Polyurethane foam CFRP with Aluminum foam
8 0 . 0 1
4 5 . 2 1
9 . 1 1
2 9 . 4 1
2 . 4 1
2 6 . 4 1
5 . 2 1
7 . 2 1
CFRP with Polyurethane foam
Total Thickness (in.) Graph 1 Optimization was determined based on the material that was both lightweight and cost effective (Low
Cost).
Deflection vs Total Thickness 14 12 ) 10 δ
( n o i t c e l f e D
GFRP with Polyurethane foam
8
GFRP with Aluminum Foam
6 4
CFRP with Aluminum foam
2 0 8 3 4 8 9 2 2 6 2 3 2 4 5 2 7 . . . . . . . . 0 5 3 9 6 9 5 . 5 . . 1 6 . 5 4 4 . . 2 . 2 0 1 2 4 1 1 4 1 1 1 4 4 1 5 1 1 1 1 1 1 1 1
CFRP with Polyurethane foam
Total Thickness (in.) Graph 2 Optimization is determined by the material with the lowest deflection and lightweight.
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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 CFRP Composites." 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.
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Appendix
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Polyurethane foam (rigid, closed cell, 0.6) Identification Designation Rigid polyurethane closed-cell foam, 0.6 specific gravity Tradenames Airex, Last-A-Foam, NidaFoam General Properties Density 0.0202 - 0.0231 lb/in^3 Price * 4.1 - 6.84 USD/lb Composition overview Composition (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 polyol Base Polymer Polymer class Thermoplastic : amorphous Polymer type PUR Polymer type full name Polyurethane plastic Filler type Unfilled Composition detail (polymers and natural materials) Polymer 100 % Foam & honeycomb properties Anisotropy ratio * 1 - 1.5 Relative density * 0.452 - 0.571 Mechanical properties Young's modulus * 0.0403 - 0.0965 10^6 psi
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Compressive modulus 0.075 - 0.0953 10^6 psi Flexural modulus * 0.124 - 0.164 10^6 psi Shear modulus 0.0217 - 0.027 10^6 psi Poisson's ratio 0.333 Shape factor 2.41 Yield strength (elastic limit) * 0.545 - 0.989 ksi Tensile strength 1.85 - 2.26 ksi Compressive strength 1.49 - 1.89 ksi Flexural strength (modulus of rupture) * 0.545 - 0.989 ksi Shear strength 1.49 - 1.82 ksi Thermal properties Maximum service temperature 275 - 351 °F Minimum service temperature -337 - -301 °F Thermal conductivity * 0.0558 - 0.0734 BTU.ft/hr.ft^2.°F Specific heat capacity 0.351 - 0.388 BTU/lb.°F Thermal expansion coefficient 50 - 80 µstrain/°F Electrical properties Electrical resistivity 9.35e18 - 6.27e19 µohm.cm Dielectric constant (relative permittivity) 3.5 - 4.54 Dissipation factor (dielectric loss tangent) 0.0626 - 0.0751 Optical properties Transparency Opaque Absorption, permeability Water absorption @ 24 hrs 0.15 - 0.19 % Durability: flammability
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Flammability Highly flammable Durability: fluids and sunlight Water (fresh) Excellent Water (salt) Excellent Weak acids Acceptable Strong acids Unacceptable Weak alkalis Acceptable Strong alkalis Limited use Organic solvents Unacceptable UV radiation (sunlight) Fair Oxidation at 500C Unacceptable Primary material production: energy, CO2 and water Embodied energy, primary production * 4.64e4 - 5.12e4 BTU/lb CO2 footprint, primary production * 4.57 - 5.05 lb/lb Water usage * 7.75e3 - 8.58e3 in^3/lb Material processing: energy Coarse machining energy (per unit wt removed) * 283 - 313 BTU/lb Fine machining energy (per unit wt removed) * 994 - 1.1e3 BTU/lb Grinding energy (per unit wt removed) * 1.78e3 - 1.97e3 BTU/lb Material processing: CO2 footprint Coarse machining CO2 (per unit wt removed) * 0.0494 - 0.0546 lb/lb Fine machining CO2 (per unit wt removed) * 0.173 - 0.192 lb/lb Grinding CO2 (per unit wt removed) * 0.311 - 0.344 lb/lb Material recycling: energy, CO2 and recycle fraction Recycle False
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Recycle fraction in current supply 0.1 % Downcycle True Combust for energy recovery True Heat of combustion (net) 9.13e3 - 1.01e4 BTU/lb Combustion CO2 1.95 - 2.15 lb/lb Landfill True Biodegrade False A renewable resource? False Notes Typical uses Core 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.
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Aluminum foam (0.5) Identification Designation Aluminum Foam (0.5) Tradenames AEROWEB 3003, AEROWEB 5052, DU RACORE 5052, DURACORE 5056 General Properties Density 0.0173 - 0.0188 lb/in^3 Price * 3.76 - 4.7 USD/lb Composition overview Composition (summary) Al/12% Si Base Al (Aluminum) Composition detail (metals, ceramics and glasses) Al (aluminum) 88 % Si (silicon) 12 % Foam & honeycomb properties Anisotropy ratio * 1 - 1.1 Cells/volume 246 - 1.64e4 /in^3 Relative density 0.17 - 0.2 Mechanical properties Young's modulus 0.682 - 0.769 10^6 psi Flexural modulus 0.682 - 0.769 10^6 psi Shear modulus * 0.254 - 0.29 10^6 psi Bulk modulus * 0.682 - 0.769 10^6 psi
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Poisson's ratio * 0.28 - 0.3 Shape factor 3 Yield strength (elastic limit) * 0.725 - 1.45 ksi Tensile strength * 2.18 - 2.9 ksi Compressive strength 0.725 - 1.45 ksi Compressive stress @ 25% strain 0.87 - 1.45 ksi Compressive stress @ 50% strain 2.18 - 2.9 ksi Flexural strength (modulus of rupture) 1.74 - 2.61 ksi Elongation 60 - 70 % strain Hardness - Vickers * 1 - 1.2 HV Fatigue strength at 10^7 cycles * 0.58 - 1.31 ksi Fatigue strength model (stress range) * 0.445 - 0.903 ksi Parameters: Stress Ratio = 0, Number of Cycles = 1e7
Fracture toughness * 1.64 - 2.09 ksi.in^0.5 Mechanical loss coefficient (tan delta) 0.0018 - 0.0023 Densification strain 0.6 - 0.7 Thermal properties Melting point 1.02e3 - 1.14e3 °F Heat deflection temperature 0.45MPa * 284 - 302 °F Heat deflection temperature 1.8MPa * 266 - 284 °F Maximum service temperature * 284 - 392 °F Minimum service temperature -459 °F Thermal conductivity 4.04 - 8.09 BTU.ft/hr.ft^2.°F Specific heat capacity 0.217 - 0.229 BTU/lb.°F Thermal expansion coefficient 10.6 - 11.1 µstrain/°F Latent heat of fusion 163 - 170 BTU/lb
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Electrical properties Electrical resistivity 31.6 - 34.7 µohm.cm Galvanic potential * -0.73 - -0.65 V Optical properties Transparency Opaque Absorption, permeability Water absorption @ 24 hrs 0.001 - 0.002 % Durability: flammability Flammability Non-flammable Durability: fluids and sunlight Water (fresh) Excellent Water (salt) Acceptable Weak acids Excellent Strong acids Excellent Weak alkalis Acceptable Strong alkalis Unacceptable Organic solvents Excellent UV radiation (sunlight) Excellent Oxidation at 500C Unacceptable Primary material production: energy, CO2 and water Embodied energy, primary production * 1.05e5 - 1.16e5 BTU/lb CO2 footprint, primary production * 14.4 - 15.9 lb/lb Water usage * 8.36e4 - 9.25e4 in^3/lb Material recycling: energy, CO2 and recycle fraction Recycle True
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Embodied energy, recycling * 1.38e4 - 1.53e4 BTU/lb CO2 footprint, recycling * 2.52 - 2.79 lb/lb Recycle fraction in current supply 0.1 % Downcycle True Combust for energy recovery False Landfill True Biodegrade False A renewable resource? False Notes Typical uses Energy absorption, Crash protection, Thermal insulation, Light weight structures, cores for sandwich structures, sound absorption, Electromagnetic shielding. Other notes Also available as an open-celled foam. Reference sources Data compiled from multiple sources. See links to the References table. .
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Glass/epoxy unidirectional composite Identification Designation Epoxy Unidirectional Composite (Glass Fiber) General Properties Density 0.0578 - 0.0704 lb/in^3 Price * 11.9 - 16.7 USD/lb Composition overview Composition (summary) Epoxy + Glass Fibers Base Polymer Polymer class Thermoset plastic Polymer type EP Polymer type full name Epoxy resin % filler (by weight) 30 - 60 % Filler type Glass fiber Composition detail (polymers and natural materials) Polymer 40 - 60 % Glass (fiber) 40 - 60 % Mechanical properties Young's modulus 5.08 - 6.53 10^6 psi Flexural modulus 5.08 - 6.53 10^6 psi Shear modulus * 2.1 - 2.7 10^6 psi Bulk modulus * 2.92 - 3.76 10^6 psi Poisson's ratio 0.05 - 0.4
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Shape factor 6.8 Yield strength (elastic limit) 43.5 - 160 ksi Tensile strength 43.5 - 160 ksi Compressive strength 52.2 - 128 ksi Flexural strength (modulus of rupture) 43.5 - 131 ksi Elongation 2 - 3 % strain Hardness - Vickers * 33 - 58 HV Fatigue strength at 10^7 cycles * 17.4 - 63.8 ksi Fracture toughness 4.55 - 18.2 ksi.in^0.5 Mechanical loss coefficient (tan delta) * 0.00278 - 0.00332 Impact properties Impact strength, notched 23 °C * 0.00177 - 0.11 BTU/in^2 Thermal properties Glass temperature 212 - 356 °F Maximum service temperature * 338 - 374 °F Minimum service temperature * -189 - -99.4 °F Thermal conductivity 0.231 - 0.693 BTU.ft/hr.ft^2.°F Specific heat capacity * 0.227 - 0.251 BTU/lb.°F Thermal expansion coefficient 4.72 - 13.9 µstrain/°F Electrical properties Electrical resistivity 1e20 - 1e21 µohm.cm Dielectric constant (relative permittivity) 3.5 - 5 Dielectric strength (dielectric breakdown) 300 - 500 V/mil Optical properties Transparency Translucent
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Durability: flammability Flammability Slow-burning Durability: fluids and sunlight Water (fresh) Excellent Water (salt) Excellent Weak acids Acceptable Strong acids Unacceptable Weak alkalis Limited use Strong alkalis Excellent Organic solvents Limited use UV radiation (sunlight) Fair Oxidation at 500C Unacceptable Primary material production: energy, CO2 and water Embodied energy, primary production * 2.04e5 - 2.25e5 BTU/lb CO2 footprint, primary production * 25.3 - 28 lb/lb Water usage * 4.26e3 - 4.71e3 in^3/lb Material processing: energy Autoclave molding energy * 8.97e3 - 9 .89e3 BTU/lb Compression molding energy * 1.43e3 - 1.58e3 BTU/lb Filament winding energy * 1.1e3 - 1.22e3 BTU/lb Pultrusion energy * 1.27e3 - 1.4e3 BTU/lb Material processing: CO2 footprint Autoclave molding CO2 * 1.67 - 1.84 lb/lb Compression molding CO2 * 0.266 - 0.294 lb/lb Filament winding CO2 * 0.206 - 0.227 lb/lb
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Pultrusion CO2 * 0.236 - 0.261 lb/lb Material recycling: energy, CO2 and recycle fraction Recycle False Recycle fraction in current supply 0.1 % Downcycle True Combust for energy recovery True Heat of combustion (net) * 5.16e3 - 5.42e3 BTU/lb Combustion CO2 * 0.968 - 1.02 lb/lb Landfill True Biodegrade False A renewable resource? False Notes Typical uses Ship and boat hulls; body shells; automobile components; cladding and fittings in construction; chemical plant.
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Epoxy/HS carbon fiber, UD composite, 0° lamina Identification Designation High 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 115-180°C, 6-7 b ar. Tradenames Cycom; Fiberdux; Scotchply General Properties Density 0.056 - 0.0571 lb/in^3 Price * 17.2 - 19.1 USD/lb Composition overview Composition (summary) Epoxy + Carbon fiber reinforcement Base Polymer Polymer class Thermoset plastic Polymer type EP Polymer type full name Epoxy resin % filler (by weight) 65 - 70 % Filler type Carbon fiber Composition detail (polymers and natural materials) Polymer 30 - 35 % Carbon (fiber) 65 - 70 % Mechanical properties Young's modulus 18.7 - 22.4 10^6 psi Compressive modulus 17.8 - 19 10^6 psi
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Flexural modulus 18.7 - 22.6 10^6 psi Shear modulus 0.542 - 0.914 10^6 psi Bulk modulus * 1.32 - 1.76 10^6 psi Poisson's ratio 0.32 - 0.34 Shape factor 7 Yield strength (elastic limit) 253 - 314 ksi Tensile strength 253 - 314 ksi Compressive strength 204 - 245 ksi Flexural strength (modulus of rupture) 253 - 314 ksi Elongation 1.2 - 1.4 % strain Hardness - Vickers * 10.8 - 21.5 HV Hardness - Rockwell M * 80 - 110 Hardness - Rockwell R * 117 - 129 Fatigue strength at 10^7 cycles * 139 - 204 ksi Fracture toughness * 9.85 - 75.2 ksi.in^0.5 Mechanical loss coefficient (tan delta) * 0.0014 - 0.0033 Impact properties Impact strength, notched 23 °C * 0.00177 - 0.0569 BTU/in^2 Thermal properties Glass temperature 212 - 356 °F Heat deflection temperature 0.45MPa * 534 - 639 °F Heat deflection temperature 1.8MPa * 482 - 581 °F Maximum service temperature * 284 - 428 °F Minimum service temperature * -189 - -99.4 °F Thermal conductivity * 2.25 - 3.81 BTU.ft/hr.ft^2.°F
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Specific heat capacity * 0.215 - 0.248 BTU/lb.°F Thermal expansion coefficient * -0.244 - 0.0889 µstrain/°F Electrical properties Electrical resistivity * 9.71e4 - 2.87e5 µohm.cm Galvanic potential 0.14 - 0.22 V Optical properties Transparency Opaque Absorption, permeability Water absorption @ 24 hrs * 0.036 - 0.0525 % Durability: flammability Flammability Slow-burning Durability: fluids and sunlight Water (fresh) Excellent Water (salt) Excellent Weak acids Acceptable Strong acids Unacceptable Weak alkalis Limited use Strong alkalis Excellent Organic solvents Limited use UV radiation (sunlight) Good Oxidation at 500C Unacceptable Primary material production: energy, CO2 and water Embodied energy, primary production * 1.95e5 - 2.15e5 BTU/lb CO2 footprint, primary production * 32.9 - 36.4 lb/lb Water usage * 3.71e4 - 4.1e4 in^3/lb
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Material processing: energy Autoclave molding energy * 8.97e3 - 9 .89e3 BTU/lb Compression molding energy * 1.43e3 - 1.58e3 BTU/lb Filament winding energy * 1.1e3 - 1.22e3 BTU/lb Pultrusion energy * 1.27e3 - 1.4e3 BTU/lb Material processing: CO2 footprint Autoclave molding CO2 * 1.67 - 1.84 lb/lb Compression molding CO2 * 0.266 - 0.294 lb/lb Filament winding CO2 * 0.206 - 0.227 lb/lb Pultrusion CO2 * 0.236 - 0.261 lb/lb Material recycling: energy, CO2 and recycle fraction Recycle False Recycle fraction in current supply 0.1 % Downcycle True Combust for energy recovery True Heat of combustion (net) * 1.34e4 - 1.41e4 BTU/lb Combustion CO2 * 3.17 - 3.33 lb/lb Landfill True Biodegrade False A renewable resource? False Notes Typical uses Lightweight structural members in aerospace, ground transport and sporting goods; springs; pressure vessels.
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GFRP with Polyurethane Foam
Price Foam($/lb.) Price GFRP ($/lb.) Modulus of Elasticity (Ef)(Psi) Thickness of Face (tf)(in) Thickness of Foam (tc)(in) Total Thickness (in.) Width(b)(in) Height (h)(in) Bending Stiffness (D) Foam Shear Modulus (Gc) Shear Stiffness (S) Bending(kb) Shear(ks) Deflection (δ)(in.) Length(L)(in.) Applied Load (P)(lbs) Max. Bendi ng Moment (M) Max. Shear Force (F) Facing Stress ( σf) Foam Stress(τc)
Density face sheet(lb.in^3) Density of Foam (lb. in^3) Volume Face Sheet (in.^3) Volume Foam (in.^) Mass face sheet (lb.) Mass Foam (lb.) Price face sheet($) Price Foam($) Total Price ($)
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4.1 11.9 5.08E+06 0.6 13 14.2 12 13.6 3.38E+09 2.17E+04 3.54E+06 0.02083 0.25 11.37 1200 1060 318000 530 5.41E+00 3.24754902 0.0578 0.0202 8640 187200 998.784 3781.44 $11,885.53 $15,503.90 $27,389.43
