Composite
materials are composed of two or more kinds of materials with different
properties. Through physical or chemical methods, these composite materials
have new properties. The comprehensive properties of composite materials are
better than those of raw materials, so as to meet different requirements. The
history use of composite materials can be traced back to ancient times. Straw
or wheat straw reinforced clay and reinforced concrete, which have been used
for hundreds of years, are composed of two materials. In the mid-1960s, carbon
fiber reinforced composites came into being, and they were used in aircraft
structures in the early1970s. Compared with the traditional materials , composite
materials have the characteristics of high specific strength and specific
modulus, good fatigue resistance, designability, and the identity of materials
and structures. The application of com posite materials in aircraft structure
has been improved continuously. The amount of composite materials used in
Airbus A350 is close to 40% of the total mass. The composite materials used in
the wing and fuselage of Boeing 787 are more than50%.Only carbon fiber
composites used on fuselage panel for Airbus A380 is more than 30 tons.