Composites 101

 With composites playing a larger role, the  plane industry can expect a flight that takes it and its customers to new heights of safety, comfort and less consumable on gas . Increasingly, aircraft designers have been turning to composites to help make their vehicles lighter, more fuel-efficient and more safe for passengers. Half of the Boeing 787 and the Airbus A350, are constructed of composite materials, and other manufacturers, like Bombardier, are getting used to having and using  composites for a variety of aircraft sections. Composites offer a very high stiffness-to-weight ratio. Very stiff fibers (usually carbon or glass) are embedded in a matrix (Some sort of plastic or very similar material ).

The fibers provide the stiffness, and the plastic  provides the glue to produce a stiff structure that is very light. Plastics and the fibers generally weigh less than metals, but the fibers have greater stiffness, providing for a larger stiffness-to-weight ratio.Since composites are composed of a matrix mixed  with a fiber, it is very rare for large cracks to develop and occur in them.

Small cracks ordinarily stop when they run into a stiff  fibers. When extreme forces are put to the structure, composites indeed may crack a little but the energy required for complete fracture is very large. From an engineering perspective, composites have some additional advantages. one, their stiffness can be messed with and can take a lot of wear and tear . Since they are stiffer in the direction of the reinforcing fibers.

Composites are normally built up with laminates where unidirectional fabric layers are stacked on  one another in different orientations to give the structure the most stiffness where it is needed.

Also composites can be adjusted  to slightly change shape in designed ways with an applied load, which allows designers and makers  to create more aerodynamically efficient wing structures. With composites, engineers also are more easily able to embed sensors into the aircraft's skin to allow pilots to watch for any damage. That capability can significantly reduce the risk  of a small problem occurring and growing into a dangerous and hazardous situation.(Strengthening) http://www.industryweek.com/none/how-composites-are-strengthening-aviation-industry

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