Fibrereinforced composite materials Engineering Materials and Processes Reference Text Section Higgins RA amp Bolton 2410 Materials for Engineers and Technicians 5th ed Butterworth Heinemann ID: 634977
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Slide1
Lecture 24 – Fibre-reinforced composite materialsSlide2
Fibre-reinforced composite materials
Engineering Materials and Processes
Reference Text
Section
Higgins RA & Bolton, 2410.
Materials for Engineers and Technicians,
5th ed, Butterworth HeinemannCh 24
Reference Text
SectionSlide3
Fibre-reinforced composite materials (Higgins 24)
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.eduSlide4
Fibre-reinforced composite materials (Higgins 24)
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 laminatesof woven textile materials.• Vehicle tyres in which vulcanised rubber is reinforced with woventextiles and steel wire.• Materials such as concrete reinforced with steel rods.Slide5
24.2 Unidirectional Composites (Higgins 24.2)
Engineering Materials and Processes
24.2.1 Relative density of composite24.2.2 Tensile strength of composite
24.2.3 Modulus of composite
HigginsSlide6
24.3 Fibres (Higgins 24.3)
Engineering Materials and Processes
24.3.1 Glass fibre24.3.2 Carbon fibre24.3.3 Boron fibre24.3.4 Aramid fibre (Kevlar)24.3.5 Other fibres
Carbon
Aramid
(Kevlar)
GlassSlide7
24.3 Fibres (Higgins 24.3)
Engineering Materials and Processes
HigginsSlide8
24.4 Matrix materials (Higgins 24.4)
Engineering Materials and Processes
• It should be stable to a temperature at which the properties of thefibre begin to deteriorate.• It must be capable of resisting any chemical attack by itsenvironment.• 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.auSlide9
24.5 Mechanical properties (Higgins 24.5)
Engineering Materials and Processes
HigginsSlide10
24.6 Fibre-composite manufacture (Higgins 24.6)
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 indiameter. 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 onlyproduce composites which are anisotropic in their properties,strength being in a direction parallel to the fibre direction.Composites manufactured as individual components. Here the fibremay be woven into a 'preform' which roughly follows the mould ordie contour. In this case, the mechanical properties will tend to bemulti-directional.Slide11
24.6 Fibre-composite manufacture (Higgins 24.6)
Engineering Materials and Processes
Higgins
24.6.1
PoltrusionSlide12
24.6 Fibre-composite manufacture (Higgins 24.6)
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 moulding24.6.5 Metal matrix compositesSlide13
24.7 Uses of fibre-reinforced composites (Higgins 24.7)
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 modulusof elasticity.• Good resistance to corrosion.• Good fatigue resistance, particularly parallel to the fibre direction.Slide14
24.7 Uses of fibre-reinforced composites (Higgins 24.7)
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.htmlSlide15
24.8 Reinforced wood (Higgins 24.8)
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 wood24.8.2 Plywood, blockboard and particleboardSlide16
24.8 Reinforced wood (Higgins 24.8)
Engineering Materials and Processes
http://www.photos-public-domain.com
24.8.3 Corrugated cardboard
Laminated boards
Complex anatomy of a carton.
Image: Carton CouncilSlide17
24.9 Reinforced concrete (Higgins 24.9)
Engineering Materials and Processes
Higgins
Steel reinforcing is designed to take tension, while concrete assumed to have zero tensile strength but takes compression.Slide18
Engineering Materials and ProcessesSlide19
Engineering Materials and ProcessesCompression tests on concreteDuctile materials simply squash (barrel). Brittle materials often fracture at 45o (due to shear stress being much lower than compressive stress).
Compression is the standard test for concrete.
Compression test for ConcreteWikipedia
24.9 Reinforced concrete
(Higgins
24.9)Slide20
Engineering Materials and ProcessesConcrete TestHigh 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 Tuberutgerscivilengr OfflineOnlineSlide21
Engineering Materials and Processes
Resources.
Ashby diagrams
Young's modulus - Density
Young's Modulus - Cost
Strength - Density
Strength - ToughnessStrength - ElongationStrength - CostStrength - Max service temperatureSpecific stiffness - Specific strengthElectrical resistivity - CostRecycle Fraction - CostEnergy content - CostSlide22
Engineering Materials and Processes
Composite MaterialsCook, Jerome T. [US]: Society of Manufacturing Engineers, c2005. DVD (17 min.).
Part A: Hand lay-up, theory, open mould chopped roving, marine, vacuum baggingPart B: Resin infusion, resin transfer, compression moulding, pultrusion, filament winding, continuous profile, bulk casting, centrifugal castingFeatures 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/COMPRecommended Viewing: All sections.VideosSlide23
Engineering Materials and Processes
Wikipedia: Fibre-reinforced plastic
Resources.
Wikipedia: Composite material
Ashby diagramsSlide24
Glossary
Engineering Materials and Processes
AnisotropicChopped fibreRovingsUnidirectionalWoven matChopped strand matFilament wound
Matrix
Poltrusion
Aramid
Carbon fibreSlide25
QUESTIONSHiggins Ch24, Newell, Timmings, Sheedy, Callister
, Ashby
Define all glossary termsExplain 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.
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.
Give five reasons for a particle to be added to a matrix – include a range of different types of particle composites.Explain how small particles can strengthen a ductile metal matrix even when the particles are rounded. (Dispersion hardened material).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.Explain why fibres are available in woven mat, chopped strand mat and filament. Give examples of each.Polyester is common with glass and epoxy with carbon. Give reasons. Give advantages and disadvantages of each matrix resin.Engineering Materials and ProcessesSlide26
QUESTIONS: Fibre CompositesHiggins Ch24, Newell, Timmings, Sheedy, Callister
, Ashby
Compare and contrast the advantages and limitations of the following systems of reinforcing concrete: (a) simple reinforcement, (b) prestressed reinforcement, (c) post-tensioned reinforcement.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.
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
Engineering Materials and Processes