A composite material consists of two or more materials combined through bonding to create a structure with distinct properties. A composite's properties depend on the properties of its individual materials, their relative amounts, sizes, shapes, orientations, and bonding. There are three main classes of composites: laminate, particulate, and fiber reinforced. Fiber reinforced plastics are the most commonly used composite in aviation due to their high strength to weight ratio. They consist of resin and high strength fibers. Composites provide benefits like weight reduction, strength customization, and corrosion resistance compared to metals, but also have disadvantages like difficulty in inspection and repair. Proper material selection and structural design are important considerations for composite structures.

1. WHAT IS A COMPOSITE
A structure consisting of two
or more different materials that
are combined together
through the process of
bonding (chemically and/or
mechanically).

2. Reinforcing element and matrix within composites.

3. The Properties of a Composite Material
Depends on
1. the properties of the individual materials,
2. the relative amount (ratio) of materials,
3. the size, shape, and distribution of the materials,
4. the degree of the bonding between materials;
and
5. the orientation of the various materials.

4. THE CLASSES OF COMPOSITES
A. LAMINATE COMPOSITE
B. PARTICULATE COMPOSITE
C. FIBER REINFORCED COMPOSITE

5. A. LAMINATE COMPOSITES

6. Bimetallic strip – Material A possesses higher thermal
expansion compared to Material B.

7. B. PARTICULATE COMPOSITE

8. FLAKE COMPOSITE

9. FIBER REINFORCED COMPOSITE

10. FILLERS
Fibrous Particulate
COMPOSITE
Fibrous Particulate
MATRIX
Ceramics
(Auminium- oxide, Carbon,
SiC, Silicon nitride, etc.)
Metallic ( Al, Al-alloys, Ti-alloys
Mg-alloys, etc.)
Polymeric
(Thermoplastic and thermosetting)

11. Type of Advanced Composite
Material:
a) Fiber Reinforced Plastic (FRP)
b) Metal-Matrix Composites(MMC)
c) Carbon-Carbon ompositesC&C)
d) Ceramic-Matrix Composites (CMC)

12. Temperature resistance of advanced composites.

13. I. Fiber reinforced Plastic (FRP)
• It is the most popular used in aviation industry due to its
high strength and/or stiffness to weight ratio.
• It is consist resin material such as epoxy, and high
strength, high modulus fibers such as Graphite,
Fiberglass and Kevlar.
• High strength and stiffness can be tailored (strength
placed in desired orientation) with tremendous weight
reduction. Typical composite structure of this type will
have 20% weight reduction and 30% stronger than
aluminum structure.
• Thermal expansion can be designed so low, or even
negative.
• Maximum service temperature of about 315 OC (600 OF)
because the matrix is Polymer type.

14. II. Metal Matrix Composites (MMC)
• Offer greater strength and stiffness than those
provided by polymers.
• It is used for operating temperatures up to 1250 OC
(2300 OF), where the condition require high strength
coupled with ductility and toughness. The fracture
toughness is also very superior.
• MMC has concentrated on Boron/Aluminum (B/Al),
Graphite/Aluminum (Gr/Al) and Silicon
Carbide/Aluminum (SiC/Al), but other potential type of
material is being studied
• Other potential ductile metal matrix: Copper,
Magnesium, Titanium, Nickel or Superalloy material.
• Other potential reinforcing element: Boron carbide,
alumina carbide; OR wire made of titanium, tungsten,
stainless steel.

15. Various metal-matrix composite materials.

16. Comparison between FRP & MMC.

17. III. Carbon Carbon Matrix (C&C)
• Consists of graphite fibers in a carbon
matrix, heat resistance material, could
operate up to 3300 OC (6000 OF), with a
strength that is 20 times of conventional
graphite,density 30% lighter (1.38 g/cm3),
thermal shock resistance,increase
strength and stiffness, self extinguishing.

18. Tensile strength vs. temperature Curves
of conventional Materials Composites

19. IV. Ceramic Matrix Composites
(CMC)
• Lightweight, high temperature strength,
and good dimensional and environmental
stability (excellent resistance to oxidation).
• Unfortunately, they are very expensive
and brittle.
• Ceramic have been used on braking
systems on commercial and military
aircraft.

20. Ceramic radome combining heat resistance with radar
signal permeability is used on patriot missiles.

21. 4. HISTORY OF COMPOSITE IN AVIATION
INDUSTRY
Early type of composite used on old aircraft.

22. Monocoque structure use in early
1930´s

23. Semi-monocoque structure

24. By 1950’s, the transition to the “all-metal”
airplane had been completed.

25. Composite structure on Boeing aircraft

26. 5. COMPOSITE APPLICATION IN
AVIATION INDUSTRY

27. APPLICATION OF COMPOSITE
MATERIALS
• FIBER-REINFORCED COMPOSITES
• 1. Aircraft and Military Application:
• Why?
• * Low weight at higher speed
• * Increased payloads
• * Tailor-made for any design
• Specific application: Carbon and Kevlar fiber composites used in:
• * Wings
• * Fuselage (Body of aircraft)
• * Rotor blades in commercial and military helicopters
• * Missile structures

28. Bottom part of Boeing 757

29. Composite structure on Boeing 777

30. 30
MALAYSIAN INSTITUTE OF AVIATION TECHNOLOGY
CO-2100 COMPOSITE IN AVIATION INDUSTRY
(AVIN)
6. THE DIFFERENT PROPERTIES BETWEEN
ADVANCED COMPOSITES STRUCTURE (FRP) FROM
METALLIC STRUCTURE
1. INHOMOGENUOUS AND
ANISOTROPIC MATERIAL

31. 2. LOW DENSITY MATERIAL

32. BRITTLE & ELASTIC CHARACTERISTIC
Failure mechanism comparison

33. Response to load comparison

34. FATIGUE LIFE
Fatigue strength of Unidirectional Composite and Aluminum.

35. 35
MALAYSIAN INSTITUTE OF AVIATION TECHNOLOGY
CO-2100 COMPOSITE IN AVIATION INDUSTRY
(AVIN)
Fatigue
Strength
of
Carbon/Graphite
Composite
with
Aluminum
7075-T6
Comparison.

36. THE ADVANTAGES OF COMPOSITE
MATERIAL
• High strength and/or stiffness to weight ratio
• Strength and stiffness can be customized.
• Low thermal expansion.
• Resistance to corrosion.
• High fatigue resistance & Reduces wear.
• Simplify construction & reduces cost.
• Simplify and reduces inspection time.
• Absorb radar microwaves (stealth capability).

37. THE DISADVANTAGES OF COMPOSITE
MATERIAL
– Manufacture & repair cure time.
– Mechanical properties affected by
temperature and moisture.
– Difficulty, reliability issue & cost in inspection.
– Low bearing and interlaminar strength.
– High material cost (getting inexpensive).
– Poor energy absorption and impact damage.
– May require lightning strike protection.

38. THE PRIMARY DESIGN
CONSIDERATIONS ON DESIGNING
COMPOSITE STRUCTURE
• MATERIAL SELECTION & COMPOSITION
• FORM & STRUCTURAL ARRANGEMENT &
DISTRIBUTION OF CONSTITUENTS
• TYPE OF APPLICATION
• OPERATIONAL ENVIRONMENT
• MISSION REQUIREMENTS

39. Strength or stiffness is fiber orientation
dependent

40. Strength and stiffness of fiber arrangement

41. Symmetric lay-up will produce better structure
properties

42. TYPE OF APPLICATION
• Determine the type of structure
• Service life
• Corrosion problems
• Method of joining
• Lightning protection

43. Typical corrosion control
composite structure

44. Lightning zone strike