Sandwich

Composite
Structure
Nanomaterials
Project
LaTecia Anderson-Jackson

Nano 704

May 1, 2013

Spring 2013
1 | P a g e


Table of Contents

NOMENCLATURE 2
ABSTRACT 3
INTRODUCTION 4
OBJECTIVE 6
PROBLEM FORMULATION 7
APPROACH 11
RESULTS/DISCUSSION 13
REFERENCES 15
APPENDIX 16




2 | P a g e

Nomenclature

b = Beam width
D = Panel bending stiffness
E
c
= Compression modulus of core
E
f
= Modulus of elasticity of facing skin
F = Maximum shear force
G
C
= Core shear modulus - in direction of applied load
G
W
= 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
t
C
= Thickness of core
t
f
= Thickness of facing skin
V = Panel parameter (used for simply supported plate)
= Calculated deflection

f
= Calculated facing skin stress

C
= Shear stress in core

3 | P a g e

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.

4 | P a g e




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
5 | P a g e

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.

6 | P a g e

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.

7 | P a g e

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

t
f
is the face sheet thickness which considered as a free variable
t
c
is thickness of the core which is considered as a free variable


Bending Stiffness

E
f
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).
t
f
is the face sheet thickness which considered as free variable
b is the beam width given as a fixed value or constraint
Shear Stiffness

8 | P a g e

b is the beam width given as a fixed value or constraint
h is the distance to the center between the two face sheets
G
c
is the core shear modulus in direction to the applied load (G
c
=G
w
)
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
9 | P a g e

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
t
f
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

10 | P a g e

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


11 | P a g e

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 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]
12 | P a g e


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.


13 | P a g e


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.
14 | P a g e


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.

$0.00
$5,000.00
$10,000.00
$15,000.00
$20,000.00
$25,000.00
$30,000.00
$35,000.00
$40,000.00
$45,000.00
1
0
.
0
8
1
2
.
5
4
1
1
.
9
1
4
.
9
2
1
4
.
2
1
4
.
6
2
1
2
.
5
1
2
.
7
P
r
i
c
e

Total Thickness (in.)
Price vs Total Thickness

GFRP with Aluminum Foam
GFRP with Polyurethane
foam
CFRP with Aluminum foam
CFRP with Polyurethane
foam
0
2
4
6
8
10
12
14
1
0
.
0
8
1
5
.
3
1
2
.
5
4
1
4
.
3
8
1
1
.
9
1
6
.
2
1
4
.
9
2
1
5
.
6
1
4
.
2
1
4
.
3
1
4
.
6
2
1
4
.
9
4
1
2
.
5
1
5
.
5
2
1
2
.
7
D
e
f
l
e
c
t
i
o
n
(

)

Total Thickness (in.)
Deflection vs Total Thickness
GFRP with Polyurethane
foam
GFRP with Aluminum Foam
CFRP with Aluminum foam
CFRP with Polyurethane
foam
15 | P a g e


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.

16 | P a g e


Appendix


17 | P a g e


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
18 | P a g e

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 strain/F
Electrical properties
Electrical resistivity 9.35e18 - 6.27e19 ohm.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
19 | P a g e

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
20 | P a g e

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.

21 | P a g e

Aluminum foam (0.5)
Identification
Designation
Aluminum Foam (0.5)
Tradenames
AEROWEB 3003, AEROWEB 5052, DURACORE 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
22 | P a g e

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 strain/F
Latent heat of fusion 163 - 170 BTU/lb
23 | P a g e

Electrical properties
Electrical resistivity 31.6 - 34.7 ohm.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
24 | P a g e

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.
.

25 | P a g e

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
26 | P a g e

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 strain/F
Electrical properties
Electrical resistivity 1e20 - 1e21 ohm.cm
Dielectric constant (relative permittivity) 3.5 - 5
Dielectric strength (dielectric breakdown) 300 - 500 V/mil
Optical properties
Transparency Translucent
27 | P a g e

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
28 | P a g e

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.

29 | P a g e

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 115-180C, 6-7 bar.
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
30 | P a g e

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
31 | P a g e

Specific heat capacity * 0.215 - 0.248 BTU/lb.F
Thermal expansion coefficient * -0.244 - 0.0889 strain/F
Electrical properties
Electrical resistivity * 9.71e4 - 2.87e5 ohm.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
32 | P a g e

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.


33 | P a g e



GFRP with
Polyurethane Foam
Price Foam($/lb.) 4.1
Price GFRP ($/lb.) 11.9
Modulus of Elasticity
(Ef)(Psi) 5.08E+06
Thickness of Face
(tf)(in) 0.6
Thickness of Foam
(tc)(in) 13
Total Thickness (in.) 14.2
Width(b)(in) 12
Height (h)(in) 13.6
Bending Stiffness (D) 3.38E+09
Foam Shear Modulus
(Gc) 2.17E+04
Shear Stiffness (S) 3.54E+06
Bending(kb) 0.02083
Shear(ks) 0.25
Deflection ()(in.) 11.37
Length(L)(in.) 1200
Applied Load (P)(lbs) 1060
Max. Bending Moment
(M) 318000
Max. Shear Force (F) 530
Facing Stress (f) 5.41E+00
Foam Stress(c) 3.24754902
Density face
sheet(lb.in^3) 0.0578
Density of Foam (lb.
in^3) 0.0202
Volume Face Sheet
(in.^3) 8640
Volume Foam (in.^) 187200
Mass face sheet (lb.) 998.784
Mass Foam (lb.) 3781.44
Price face sheet($) $11,885.53
Price Foam($) $15,503.90
Total Price ($) $27,389.43
34 | P a g e



CFRP with
Polyurethane Foam
Price Foam($/lb.) 4.1
Price CFRP ($/lb.) 17.2
Modulus of Elasticity
(Ef)(Psi) 1.87E+07
Thickness of Face
(tf)(in) 0.2
Thickness of Foam
(tc)(in) 14.5
Total Thickness (in.) 14.9
Width(b)(in) 12
Height (h)(in) 14.7
Bending Stiffness (D) 4.85E+09
Foam Shear Modulus
(Gc) 2.17E+04
Shear Stiffness (S) 3.83E+06
Bending(kb) 0.02083
Shear(ks) 0.25
Deflection ()(in.) 7.95
Length(L)(in.) 1200
Applied Load (P)(lbs) 1060
Max. Bending
Moment (M) 318000
Max. Shear Force (F) 530
Facing Stress (f) 15.022676
Foam Stress(c) 3.0045351
Density face
sheet(lb.in^3) 0.056
Density of Foam (lb.
in^3) 0.0202
Volume Face Sheet
(in.^3) 2880
Volume Foam (in.^) 208800
Mass face sheet (lb.) 322.56
Mass Foam (lb.) 4217.76
Price face sheet($) $5,548.03
Price Foam($) $17,292.82
Total Price ($) $22,840.85
CFRP with Aluminum
Foam
Price Foam($/lb.) 3.76
Price CFRP ($/lb.) 17.2
Modulus of Elasticity
(Ef)(Psi) 1.87E+07
Thickness of Face
(tf)(in) 0.3
Thickness of Foam
(tc)(in) 9.48
Total Thickness (in.) 10.08
Width(b)(in) 12
Height (h)(in) 9.78
Bending Stiffness (D) 3.22E+09
Foam Shear Modulus
(Gc) 2.54E+04
Shear Stiffness (S) 2.98E+06
Bending(kb) 0.02083
Shear(ks) 0.25
Deflection ()(in.) 11.95746079
Length(L)(in.) 1200
Applied Load (P)(lbs) 1060
Max. Bending Moment
(M) 318000
Max. Shear Force (F) 530
Facing Stress (f) 15.05339696
Foam Stress(c) 4.516019087
Density face
sheet(lb.in^3) 0.056
Density of Foam (lb.
in^3) 0.0173
Volume Face Sheet
(in.^3) 4320
Volume Foam (in.^) 136512
Mass face sheet (lb.) 483.84
Mass Foam (lb.) 2361.6576
Price face sheet($) $8,322.05
Price Foam($) $8,879.83
Total Price ($) $17,201.88