Composites in Aviation

• Weight is always a critical factor in aviation.

• Heavier the Craft the more power to lift it & more fuel is required.

• Now –a-days advanced composites materials are used to build wider, faster, lighter & more durable aircrafts.

• In the beginning, the frames of air flying machines were made of wood & covered with cloths.

Advanced Composite Material

• With few variations in persisted models, aluminium became the material of choice & several aircrafts were produced .

• In first war Al-made aircrafts were used but could not exist for a long time due to following shortcomings.

Soon become apparent

Hard to form smooth & complex shapes

Subjected to corrosion

Fatigue faliures under stress

• Slowly many these problems were dressed ,& aircrafts were built with composite materials

• Modern composites rely on matrix that can be molded into complex shapes

• In earliar applications bakelite, a liquid phenolicresin combined with weakly reinforcement like Sodas , paper or cloth had been used for aircraft

• However these phenolicresin composites had some serious limitations

• They were relatively weak & brittle

• The first uses of bakelite in aviation were to make small parts like insulators & control knobes inside the aircraft

• Then in 1930’s Loans Corning developed fiber glass composites.

• Early fiber glass still used phenolic resin , so the composites were still brittle, but they were quite strong

• This strong & moldable fiber glass was not suitable for aircraft parts , but was perfect for creating parts

• Duplex aircraft company used fiberglass composites as forming die tools to produce prototype metal aircraft parts.

• At the approach of second world war, several advances occured in material science including polymer chemistry

• New synthetic resins including polyester resin & epoxy resin were developed & brittle matrix problem was eliminated.

• This new generation of composites was very deafly.

• During war years, composites were spread throughout the military crafts

Fiber glass Air Duks

Engine cover called nicely

Radon to protect delicate radar electronics

• War time metal shortage gave composite industry & other boosts & USA Govt. began ordering new training aircraft with composite airframes.

• 15 years later the war was long over ,But the global pressure was building.

• The cold war in space race was hungry for new technology & new technology demanded new materials

• In early 1960’s when fiber produced from Boron metal the with addition of epoxy resin matrix .

• This boron epoxy composite was

the first ACM (Advanced

Composite Material)

• As it was expensive so its use was

restricted for almost entirely

military applications including

Horizontal Stabilizer F-14, Tomb

Cat & B-1 Bomber.

• Another ACM developed in

1960’s was carbon fiber

composite

• It was more stronger & lighter

than fiber glass & much less

expensive than boron fiber.

• It was perfect both for military & commercial Aviation.

• C-fiber composite has been used extensively for internal structural parts & exterior skins in F1-17 Stealth Fighter & Beat U Stealth Bomber.

• In industrial aviation both Bowling 787 & Air bus A350XWB used C-fiber (ACM) for over 15% for each craft structure .

• Another reinforcing fiber that used in

aerospace application was Armed.

• The best known aramid is “Kevlar” comes

from family of fiber that can absorb &

disappear numerous amount of energy.

• Aramid composites are often used for impact

protection like armor & to reinforce

helicopter's radar blades.

Armed Kevlar

• Composites are made for Aviation as they are the perfect designer materials for aerospace industry

• They can bear many challenges due to following characteristics

Light

Strong

Stable

Flexible

Chemical resistance

heat resistance

Shock resistance

And even bullet

proof

• In aerospace if it can

be dreamed , it can

be built.