Editing Composite material (section)

===Types of fibers and mechanical properties===
The most common types of fibers used in industry are [[glass fiber]]s, [[carbon fibers]], and [[kevlar]] due to their ease of production and availability. Their mechanical properties are very important to know, therefore the table of their mechanical properties is given below to compare them with S97 [[steel]].<ref>{{cite web |title=Carbon Fibre, Tubes, Profiles – Filament Winding and Composite Engineering |url=http://www.performance-composites.com/carbonfibre/carbonfibre.asp |website=www.performance-composites.com |access-date=2020-05-22 |archive-date=2020-05-05 |archive-url=https://web.archive.org/web/20200505133007/http://www.performance-composites.com/carbonfibre/carbonfibre.asp |url-status=live}}</ref><ref>{{cite web |title=Composite Manufacturing {{!}} Performance Composites|url=https://www.performancecomposites.com/|website=www.performancecomposites.com|access-date=2020-05-22|archive-date=2020-05-03|archive-url=https://web.archive.org/web/20200503120735/http://www.performancecomposites.com/|url-status=live}}</ref><ref>{{cite web |title=Composite Materials • Innovative Composite Engineering |url=http://www.innovativecomposite.com/materials/ |website=Innovative Composite Engineering |language=en-US |access-date=2020-05-22 |archive-date=2020-05-05 |archive-url=https://web.archive.org/web/20200505134923/http://www.innovativecomposite.com/materials/ |url-status=live}}</ref><ref>{{cite web |title=Reinforcement Fabrics – In Stock for Same Day Shipping {{!}} Fibre Glast|url=https://www.fibreglast.com/category/Composite-Fabrics|website=www.fibreglast.com|access-date=2020-05-22|archive-date=2020-07-16|archive-url=https://web.archive.org/web/20200716204826/https://www.fibreglast.com/category/Composite-Fabrics|url-status=live}}</ref> The angle of fiber orientation is very important because of the anisotropy of fiber composites (please see the section "[[#Physical properties|Physical properties]]" for a more detailed explanation). The mechanical properties of the composites can be tested using standard [[mechanical testing]] methods by positioning the samples at various angles (the standard angles are 0°, 45°, and 90°) with respect to the orientation of fibers within the composites. In general, 0° axial alignment makes composites resistant to longitudinal bending and axial tension/compression, 90° hoop alignment is used to obtain resistance to internal/external pressure, and ± 45° is the ideal choice to obtain resistance against pure torsion.<ref>{{cite web |title=Filament Winding, Carbon Fibre Angles in Composite Tubes |url=http://www.performance-composites.com/carbonfibre/fibreangles.asp |website=www.performance-composites.com |access-date=2020-05-22 |archive-date=2020-05-05 |archive-url=https://web.archive.org/web/20200505132959/http://www.performance-composites.com/carbonfibre/fibreangles.asp |url-status=live}}</ref>

====Mechanical properties of fiber composite materials====
{| class="wikitable"
|+Fibres @ 0° (UD), 0/90° (fabric) to loading axis, Dry, Room Temperature, V<sub>f</sub> = 60% (UD), 50% (fabric) Fibre / Epoxy Resin (cured at 120&nbsp;°C)<ref name=":2">{{cite web |title=Mechanical Properties of Carbon Fibre Composite Materials |url=http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp |website=www.performance-composites.com |access-date=2020-05-22 |archive-date=2020-06-03 |archive-url=https://web.archive.org/web/20200603174526/http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp |url-status=live}}</ref>
|
!Symbol
!Units
!Standard
Carbon Fiber

Fabric
!High Modulus
Carbon Fiber

Fabric
!E-Glass
Fibre Glass
Fabric
!Kevlar
Fabric
!Standard
Unidirectional

Carbon Fiber

Fabric
!High Modulus

Unidirectional

Carbon Fiber

Fabric
!E-Glass
Unidirectional

Fiber Glass
Fabric
!Kevlar
Unidirectional
Fabric
!Steel
S97
|-
!Young's Modulus 0°
|E1
|GPa
|70
|85
|25
|30
|135
|175
|40
|75
|207
|-
!Young's Modulus 90°
|E2
|GPa
|70
|85
|25
|30
|10
|8
|8
|6
|207
|-
!In-plane Shear Modulus
|G12
|GPa
|5
|5
|4
|5
|5
|5
|4
|2
|80
|-
!Major Poisson's Ratio
|v12
|
|0.10
|0.10
|0.20
|0.20
|0.30
|0.30
|0.25
|0.34
| –
|-
!Ult. Tensile Strength 0°
|Xt
|MPa
|600
|350
|440
|480
|1500
|1000
|1000
|1300
|990
|-
!Ult. Comp. Strength 0°
|Xc
|MPa
|570
|150
|425
|190
|1200
|850
|600
|280
| –
|-
!Ult. Tensile Strength 90°
|Yt
|MPa
|600
|350
|440
|480
|50
|40
|30
|30
| –
|-
!Ult. Comp. Strength 90°
|Yc
|MPa
|570
|150
|425
|190
|250
|200
|110
|140
| –
|-
!Ult. In-plane Shear Stren.
|S
|MPa
|90
|35
|40
|50
|70
|60
|40
|60
| –
|-
!Ult. Tensile Strain 0°
|ext
|%
|0.85
|0.40
|1.75
|1.60
|1.05
|0.55
|2.50
|1.70
| –
|-
!Ult. Comp. Strain 0°
|exc
|%
|0.80
|0.15
|1.70
|0.60
|0.85
|0.45
|1.50
|0.35
| –
|-
!Ult. Tensile Strain 90°
|eyt
|%
|0.85
|0.40
|1.75
|1.60
|0.50
|0.50
|0.35
|0.50
| –
|-
!Ult. Comp. Strain 90°
|eyc
|%
|0.80
|0.15
|1.70
|0.60
|2.50
|2.50
|1.35
|2.30
| –
|-
!Ult. In-plane shear strain
|es
|%
|1.80
|0.70
|1.00
|1.00
|1.40
|1.20
|1.00
|3.00
| –
|-
!Density
|
|g/cc
|1.60
|1.60
|1.90
|1.40
|1.60
|1.60
|1.90
|1.40
| –
|}
<br/>
{| class="wikitable"
|+Fibres @ ±45 Deg. to loading axis, Dry, Room Temperature, Vf = 60% (UD), 50% (fabric)<ref name=":2"/>
!
!Symbol
!Units
!Standard
Carbon Fiber
!High Modulus
Carbon Fiber
!E-Glass
Fiber Glass
!Standard
Carbon Fibers

Fabric
!E-Glass
Fiber Glass
Fabric
!Steel
!Al
|-
!Longitudinal Modulus
|E1
|GPa
|17
|17
|12.3
|19.1
|12.2
|207
|72
|-
!Transverse Modulus
|E2
|GPa
|17
|17
|12.3
|19.1
|12.2
|207
|72
|-
!In Plane Shear Modulus
|G12
|GPa
|33
|47
|11
|30
|8
|80
|25
|-
!Poisson's Ratio
|v12
|
|.77
|.83
|.53
|.74
|.53
|
|
|-
!Tensile Strength
|Xt
|MPa
|110
|110
|90
|120
|120
|990
|460
|-
!Compressive Strength
|Xc
|MPa
|110
|110
|90
|120
|120
|990
|460
|-
!In Plane Shear Strength
|S
|MPa
|260
|210
|100
|310
|150
|
|
|-
!Thermal Expansion Co-ef
|Alpha1
|Strain/K
|2.15 E-6
|0.9 E-6
|12 E-6
|4.9 E-6
|10 E-6
|11 E-6
|23 E-6
|-
!Moisture Co-ef
|Beta1
|Strain/K
|3.22 E-4
|2.49 E-4
|6.9 E-4
|
|
|
|
|}

==== Carbon fiber & fiberglass composites vs. aluminum alloy and steel ====

Although strength and stiffness of [[steel]] and [[Aluminium alloy|aluminum alloy]]s are comparable to fiber composites, [[specific strength]] and [[Specific modulus|stiffness]] of composites (i.e. in relation to their weight)  are significantly higher.

{| class="wikitable"
|+Comparison of Cost, Specific Strength, and Specific Stiffness<ref>{{cite web |title=Carbon Fiber Composite Design Guide |url=https://www.performancecomposites.com/about-composites-technical-info/124-designing-with-carbon-fiber.pdf |website=www.performancecomposites.com |access-date=2020-05-22 |archive-date=2020-10-30 |archive-url=https://web.archive.org/web/20201030130724/https://www.performancecomposites.com/about-composites-technical-info/124-designing-with-carbon-fiber.pdf |url-status=live}}</ref>
|
|'''Carbon Fiber Composite (aerospace grade)'''
|'''Carbon Fiber Composite (commercial grade)'''
|'''Fiberglass Composite'''
|'''Aluminum 6061 T-6'''
|'''Steel,'''

'''Mild'''
|-
|'''Cost $/LB'''
|$20 – $250+
|$5 – $20
|$1.50 – $3.00
|$3
|$0.30
|-
|'''Strength (psi)'''
|90,000 – 200,000
|50,000 – 90,000
|20,000 – 35,000
|35,000
|60,000
|-
|'''Stiffness (psi)'''
|10 x 10<sup>6</sup>– 50 x 10<sup>6</sup>
|8 x 10<sup>6</sup> – 10 x 10<sup>6</sup>
|1 x 10<sup>6</sup> – 1.5 x 10<sup>6</sup>
|10 x 10<sup>6</sup>
|30 x 10<sup>6</sup>
|-
|'''Density (lb/in3)'''
|0.050
|0.050
|0.055
|0.10
|0.30
|-
|'''<u>Specific Strength</u>'''
|<u>1.8 x 10<sup>6</sup> – 4 x 10<sup>6</sup></u>
|<u>1 x 10<sup>6</sup> – 1.8 x 10<sup>6</sup></u>
|<u>363,640–636,360</u>
|<u>350,000</u>
|<u>200,000</u>
|-
|'''<u>Specific Stiffness</u>'''
|<u>200 x 10<sup>6</sup> – 1,000 x 10<sup>6</sup></u>
|<u>160 x 10<sup>6</sup> – 200 x 10<sup>6</sup></u>
|<u>18 x 10<sup>6</sup> – 27 x 10<sup>6</sup></u>
|<u>100 x 10<sup>6</sup></u>
|<u>100 x 10<sup>6</sup></u>
|}