This document discusses the use of composite materials in aircraft structures. It defines composites as materials made from two or more constituent materials combined to produce improved properties. Composites provide benefits for aircraft like high strength to weight ratios, corrosion and impact resistance, and the ability to form complex shapes. Common composite constituents in aircraft are fiber reinforcements within polymer, metal, or ceramic matrices. Applications of composites in aircraft include fuselage and wing skins due to their weight savings over metal. While composites provide advantages, their production is more expensive and recycling presents challenges compared to conventional materials.

1. COMPOSITE MATERIALS IN
AIRCRAFT STRUCTURES
Prepared By:
RAHUL DUBEY

2. Overview
 Composite Materials: A Brief Introduction
Why Composites?
Advantages of Composites
Applications in Aerospace Industry
Limitations of Composites
Conclusion
References

3. Introduction
Modern technologies require materials with
unusual combination of properties
Cannot be met by conventional materials.
 Aerospace EngineeringApplications
 Low density, strong & stiff, and abrasion,
corrosion & impact resistant material.

4. Composite Materials
Material property combinations have been
extended
Exhibit a significant proportion of properties of
constituent phases
Number of composites occur in nature
1.Wood
 Strong & flexible cellulose fibers held together
by stiffer lignin
2. Bone
 Soft & strong collagen surrounds hard & brittle
apatite

5. Definition
 A composite material in the present context
 A combination of two or more materials with certain
desired properties or improved properties
 The original identity of dispersed (reinforcement)
phase should be retained during manufacturing
and/service
 Multiphase alloys & ceramics are not composites
 Most composites have been created to improve the
combination of mechanical properties
 Stiffness, toughness, ambient & high temperature
strength

6. Why Composites?
To enhance the material properties &
performance efficiency
To design materials with combination of
desired properties

7. Advantages of Composites
 High strength/stiffness to weight ratio
 Energy efficient
 Corrosion and weather resistant
 Properties for specific design conditions
 Directional properties
 Easy to make complex shapes

8. Constituents
 Reinforcement - Discontinuous phase
(constituent)
 Matrix - Continuous phase (constituent)
Polymer Composite

9. Constituents
Reinforcements
 principal load bearing member
Matrix
 provides a medium for binding and holding the
reinforcements or fillers together into a solid
 protects the reinforcement from environmental
degradation
 serves to transfer load from one insert (fibre,
flake or particles) to the other
 provides finish, colour, texture, durability and
other functional properties

11. Classification
Nature of Origin
 Natural Composites
 Man-made Composites
Matrix
 Polymer Matrix Composites (PMC)
 Metal Matrix Composites (MMC)
 Ceramic Matrix Composites (CMC)
Reinforcements
 Fibre & Particulate Composites
 Macro-, Micro- and Nano-composites

12. Purpose of Second Phase
to enhance matrix properties
 PMC: to increase E, σy,TS, creep resistance
 MMC: to increase σy,TS, creep resistance
 CMC: to increase Kc

15. Applications of Composites in
Aerospace
Starting with first fully-composite glider
“phonix”, Fibre reinforced plastics (FRPs)
have gained importance in aerospace
industry.
2000 tons of finished composite parts, with a
value of 760 million dollars were produced by
European aerospace industry in 2000.

17. V/STOL (vertical and/or short take-off and landing); SST (supersonic transport)

18. Composites in Military
Aircraft
Aircraft Component Material Weight
Saving
(%)
F-14 Skin on the horizontal
stabiliser box
B-Epoxy 19
F-11 Underwing fairings C-Epoxy -
F-15 Fin, stabiliser skins B-Epoxy 25
F-16 Skins on vertical fin box, Fin
leading edge
C-Epoxy 23
F/A-18 Wing skins, Horizontal &
vertical tail boxes, wing & tail
control surfaces
C-Epoxy 35
AV-8B Wing skins & sub structures,
forward fuselage, horizontal
stabiliser, ailerons
C-Epoxy 25

22. Limitations of Composites
 Composites are more expensive than conventional
materials on a cost to cost basis
 The chances of formation of defects at the interface
are high
 Most of the fibre reinforced composites are
anisotropic in nature
 The production rate of composites is generally low
 Database on the properties of different composites
is not available
 Recycling is another hurdle for the wide usage of
 composites

24. In Conclusion...

25. References
 Agarwal, B.D., L.J. Broutman and K. Chandrashekhara.
2006. Analysis and performance of fiber composites, 3rd edn.,
NewYork:JohnWiley & sons.
 Chawla, K.K. 2012. Composite materials:Science and
engineering, 3rd edn., NewYork, USA: Springer-Verlag Inc.
 Mallick, P.K. 2008. Fiber-reinforced composites, 3rd edn.,
Boca Raton, USA: CRC Press.
 Ajayan, P.M., L.S. Schadler and P.V. Braun. 2003.
Nanocomposite science and technology, Morlenbach,
Germany:WILEY-VCH.
 Balasubramanian, M. 2013. Composite materials and
processing, Boca Raton, USA: CRC Press.
 Suresh, S., Mortensen,A. and Needleman,A. (Eds.) 1993.
Fundamentals