26-04-2011, 10:11 AM
Presented By
Mallappa.IG
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Introduction.
Composite materials are particularly attractive to aviation and aerospace applications because of their exceptional strength and stiffness-to-density ratios and superior physical properties.
As the technology matured, the use of composite materials for primary structures such as wings and fuselages has increased. Initial applications of composite materials to aircraft structures were in secondary structures such as fairings, small doors and control surfaces.
With their unique combination of properties such as low weight, high strength, low flammability, smoke density and heat release, non-toxicity and durability, composites are ideal for many aerospace applications, both for interior and exterior components.
Overview of Composite Materials
• Composites are essentially plastics reinforced with carbon fibres.
• Emergence of strong and stiff reinforcements like carbon fibre along with advances in polymer research to produce high performance resins as matrix materials have helped meet the challenges posed by the complex designs of modern aircraft.
Composite Materials
1 .Composite materials can provide a much better strength-to-weight ratio than any metals.
2. Carbon fibres, each no larger than a human hair, are set into resin to form sheets.
Layers of a Composite Tube
Modeled Tube in ANSYS
Matrix
Matrix Considerations
End Use Temperature
Toughness
Cosmetic Issues
Flame Retardant
Processing Method
Adhesion Requirements
Reinforcement for Composites
Different types of reinforcement for composites:
(a) particle reinforcement;
(b) short fiber reinforcement;
© continuous fiber reinforcement;
(d) laminate reinforcement.
Fabrication
Manufacturing engineers are, similarly, wrestling with unfamiliar difficulties. Problems with wrinkling of the fibres in the fabrication process, resulting in a loss of stiffness and strength in the finished component.
Different Composites
(a) Transverse section of a boron fiber reinforced aluminum composite.
(b) Section of a short alumina fiber/aluminum matrix composite.
© Deeply etched transverse section of a composite
