ENMAT101A Engineering Materials and Processes

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TAFE NSW
-
Technical and Further Education Commission

www.highered.tafensw.edu.au




ENMAT101A Engineering Materials and Processes

Associate Degree of Applied Engineering

(Renewable Energy Technologies)

Lecture
24


Fibre
-
reinforced composite materials

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-
Technical and Further Education Commission

Fibre
-
reinforced composite materials

EMMAT101A Engineering Materials and Processes

Reference Text

Section

Higgins RA & Bolton, 2410.
Materials for Engineers and Technicians,
5th
ed
, Butterworth Heinemann

Ch 24

Reference Text

Section

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Technical and Further Education Commission

Fibre
-
reinforced composite materials
(Higgins

24)

EMMAT101A Engineering Materials and Processes

Wood can be thought of as a fibre composite: Fibres are the cells
(tracheids) and glued together by the matrix (lignin).

http://woodmagic.vt.edu

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Technical and Further Education Commission

Fibre
-
reinforced composite materials
(Higgins

24)

EMMAT101A Engineering Materials and Processes

24.1.1 Man
-
made fibre
-
reinforced composites

• Matrix materials, such as thermosetting or thermoplastics polymers

and some low
-
melting point metals, reinforced with fibres of carbon,

glass or organic polymer.

• Polymers, usually thermosetting, reinforced with fibres or laminates

of woven textile materials.

• Vehicle tyres in which vulcanised rubber is reinforced with woven

textiles and steel wire.

• Materials such as concrete reinforced with steel rods.

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24.2 Unidirectional Composites
(Higgins

24.2)

EMMAT101A Engineering Materials and Processes

24.2.1 Relative density of composite

24.2.2 Tensile strength of composite

24.2.3 Modulus of composite


Higgins

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24.3 Fibres
(Higgins

24.3)

EMMAT101A Engineering Materials and Processes

24.3.1 Glass fibre

24.3.2 Carbon fibre

24.3.3 Boron fibre

24.3.4
Aramid

fibre (Kevlar)

24.3.5 Other fibres

Carbon

Aramid

(Kevlar)

Glass

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24.3 Fibres
(Higgins

24.3)

EMMAT101A Engineering Materials and Processes

Higgins

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Technical and Further Education Commission

24.4 Matrix materials
(Higgins

24.4)

EMMAT101A Engineering Materials and Processes

• It should be stable to a temperature at which the properties of the

fibre begin to deteriorate.

• It must be capable of resisting any chemical attack by its

environment.

• It should not be affected by moisture.


24.4.1 Thermosetting resins

24.4.2 Thermoplastic polymers

24.4.3 Metals


http://www.glowpaint.com.au

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24.5 Mechanical properties
(Higgins

24.5)

EMMAT101A Engineering Materials and Processes

Higgins

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Technical and Further Education Commission

24.6 Fibre
-
composite manufacture
(Higgins

24.6)

EMMAT101A Engineering Materials and Processes

Higgins


Rovings. A 'roving' of glass fibres, which may be several kilometres

in length, consists of 'strands', or bundles of filaments wound on to a

'creel'. A 'strand' contains some 200 filaments, each about 10 um in

diameter. Bundles of continuous carbon fibres are known as 'tows'.


Woven fabrics in various weave types.


Chopped fibres, usually between 1 mm and 50 mm long.


Continuously produced sections (rod, tube or channel), or sheet,

from which required lengths can be cut. Such a process can only

produce composites which are anisotropic in their properties,

strength being in a direction parallel to the fibre direction.


Composites manufactured as individual components. Here the fibre

may be woven into a '
preform
' which roughly follows the mould or

die contour. In this case, the mechanical properties will tend to be

multi
-
directional.

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24.6 Fibre
-
composite manufacture
(Higgins

24.6)

EMMAT101A Engineering Materials and Processes

Higgins

24.6.1
Poltrusion


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Technical and Further Education Commission

24.6 Fibre
-
composite manufacture
(Higgins

24.6)

EMMAT101A Engineering Materials and Processes

Fibreglass/polyester Boat Hull
http://rampageous.com

24.6.2 'Hand
-
and
-
spray' placement

24.6.3 Press moulding

24.6.4 Resin
-
transfer moulding

24.6.5 Metal matrix composites


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24.7 Uses of fibre
-
reinforced composites
(Higgins

24.7)

EMMAT101A Engineering Materials and Processes

Higgins

The most important of these materials commercially are polymer matrix

composites reinforced with either glass, carbon or
aramid

fibres.


The following characteristics of fibre composites commend their use:

• Low relative density and hence high specific strength and modulus

of elasticity.

• Good resistance to corrosion.

• Good fatigue resistance, particularly parallel to the fibre direction.

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Technical and Further Education Commission

24.7 Uses of fibre
-
reinforced composites
(Higgins

24.7)

EMMAT101A Engineering Materials and Processes

This wind turbine blade is fibreglass


the fibres can be clearly seen.
The tower itself is usually steel.

Oldenburg in northern Germany 2006


http://www.solaripedia.com/13/25
/dangers_of_wind_power.html

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Technical and Further Education Commission

24.8 Reinforced wood
(Higgins

24.8)

EMMAT101A Engineering Materials and Processes

Higgins

The development of strong synthetic resin adhesives some years ago

resulted in much progress in the use of timber as a constructional

material. Also called ‘engineered wood’.


24.8.1 Laminated wood

24.8.2 Plywood,
blockboard

and

particleboard


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Technical and Further Education Commission

24.8 Reinforced wood
(Higgins

24.8)

EMMAT101A Engineering Materials and Processes

http://www.photos
-
public
-
domain.com

24.8.3 Corrugated cardboard


Laminated boards

Complex anatomy of a
carton.

Image: Carton Council

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Technical and Further Education Commission

24.9 Reinforced concrete
(Higgins

24.9)

EMMAT101A Engineering Materials and Processes

Higgins

Steel reinforcing is designed to take tension, while concrete assumed
to have zero tensile strength but takes compression.

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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

TAFE NSW
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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

Compression tests on concrete


Ductile materials simply squash (barrel).
Brittle materials often fracture at 45
o

(due to
shear stress being much lower than
compressive stress).

Compression is the standard test for
concrete.




Compression test for Concrete

Wikipedia


24.9 Reinforced concrete
(Higgins

24.9)

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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

Concrete Test

High Strength Concrete


Concrete is not usually this
strong, so it doesn’t usually
explode like this…


The numbers:
(Imperial/US units)

15.9
ksi

or 200,000
lbs

on a 4"
diam

cylinder.


Convert this to metric = 110Mpa


Concrete is usually about 20MPa,
structural about 40MPa, and higher
strength usually prefabricated since
the W/C ratio must be very low (dry).

Compression test for Concrete

You Tube

rutgerscivilengr



Offline

Online

TAFE NSW
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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

Resources.

Ashby diagrams

Young's modulus
-

Density

Young's Modulus
-

Cost

Strength
-

Density

Strength
-

Toughness

Strength
-

Elongation

Strength
-

Cost

Strength
-

Max service temperature

Specific stiffness
-

Specific strength

Electrical resistivity
-

Cost

Recycle Fraction
-

Cost

Energy content
-

Cost

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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

Composite Materials

Cook, Jerome T. [US]: Society of Manufacturing Engineers, c2005.
DVD (17 min.).

Part A: Hand lay
-
up, theory, open mould chopped roving, marine, vacuum
bagging

Part B: Resin infusion, resin transfer, compression moulding,
pultrusion
,
filament winding, continuous profile, bulk casting, centrifugal casting

Features an explanation of the mechanical properties of
thermoset

fiber
-
reinforced composites. The primary types of reinforcement materials are
examined as well as the major matrix materials. The use of thermoplastic
composite materials is also highlighted.

Mt Druitt College Library
:


DVD 620.192/COMP

Recommended Viewing: All sections.


Videos

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Technical and Further Education Commission

EMMAT101A Engineering Materials and Processes

Wikipedia: Fibre
-
reinforced plastic

Resources.

Wikipedia: Composite material

Ashby diagrams

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Technical and Further Education Commission

Glossary

EMMAT101A Engineering Materials and Processes

Anisotropic

Chopped fibre

Rovings

Unidirectional

Woven mat

Chopped strand mat

Filament wound

Matrix

Poltrusion

Aramid

Carbon fibre




TAFE NSW
-
Technical and Further Education Commission

QUESTIONS

Higgins Ch24, Newell,
Timmings
,
Sheedy
,
Callister
, Ashby


1.
Define all glossary terms

2.
Explain the issues of making strong concrete regarding water ratio, cement ratio,
aggregate and sand, curing time and temperature, curing humidity. Explain what
would be done to achieve high strength and low shrinkage.

3.
What is a
cermet

and what are they used for? Give some examples of cermets
and explain what properties they have that make them suitable for their purpose.

4.
Give five reasons for a particle to be added to a matrix


include a range of
different types of particle composites.

5.
Explain how small particles can strengthen a ductile metal matrix even when the
particles are rounded. (Dispersion hardened material).

6.
Obsidian is a naturally occurring (usually dark) volcanic rock. Granite has large
visible crystals and forms deep underground. Which one is more likely to be a
glassy structure? Explain.

7.
Explain why fibres are available in woven mat, chopped strand mat and filament.
Give examples of each.

8.
Polyester is common with glass and epoxy with carbon. Give reasons. Give
advantages and disadvantages of each matrix resin.

EMMAT101A Engineering Materials and Processes

TAFE NSW
-
Technical and Further Education Commission

QUESTIONS: Fibre Composites

Higgins Ch24, Newell,
Timmings
,
Sheedy
,
Callister
, Ashby


9.
Compare and contrast the advantages and limitations of the following systems of
reinforcing concrete: (a) simple reinforcement, (b) prestressed reinforcement, (c)
post
-
tensioned reinforcement.

10.
Explain what is meant by the particle hardening of a composite material and the
dispersion hardening of a composite material. In each case give an example of
such a material, together with a typical application.

11.

Compare the four main types of water storage tank for domestic purposes:
Polyethylene, fibreglass, galvanised steel and concrete.
See
http://www.bushmantanks.com.au/web/page/there
-
is
-
a
-
difference
-
between
-
tank
-
materials
-
/news/4531



EMMAT101A Engineering Materials and Processes