The most primitive composite materials were straw and mud in the form of bricks for building construction. The Biblical book of Exodus tells of the Israelites that were oppressed by Pharaoh and forced to make "bricks without straw". Today we use shower stalls and bath tubs made of fiberglass, a type of composite.
Fibre
A fibre (also spelled as fiber) is a piece of material which is long, thin and flexible, like a length of thread. Plant fibres are the basis of fabric such as cotton. Silk and wool fibres come from animals. In the 20th century many artificial fibres were invented like nylon and polyester.
They are very important in the structure of plants and animals, because they hold tissues together.
There are many uses for fibres. They can be spun together into filaments, thread, string or rope. They can be woven in fabric or in composite materials
Natural fibers include those made by plants, animals, and geological processes. They can be classified according to where they came from:
Man-made are fibers that are changed by man. Man-made fibers consist of regenerated fibers and synthetic fibers.
Semi-synthetic fibers are made from raw materials with natural long-chain polymer structures. They are only changed and partially degraded by chemical processes. The first semi-synthetic fiber is rayon. Most semi-synthetic fibers are cellulose regenerated fibers.
Cellulose fibers are a type of man-made fibers, regenerated from natural cellulose. The cellulose comes from many sources: rayon comes from tree wood fiber, bamboo fiber comes from bamboo, seacell comes from seaweed, etc.
Some examples of this type of fiber are:
Synthetic fibers come from synthetic materials such as petrochemicals.
Metallic fibers can be gotten from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron.
Carbon fibers are fibers that are mostly made up of carbon atoms. Carbon fibers are often based on oxidizing carbonized polymers through pyrolysis like PAN.
In silicon carbide fibers the basic polymers are not hydrocarbons but polymers. About 50% of the carbon atoms are replaced by silicon atoms.
Fiberglass are also man-made fibers that come from natural raw materials. It is made from a specific type glass, and optical fiber, which is made from purified natural quartz.
Fibre-reinforced polymer
A fibre-reinforced polymer (also fibre-reinforced plastic ("FRP")) is a composite material that consists of a polymer matrix that is reinforced with fibres. The fibres are usually fibreglass, carbon, or aramid, the polymer is usually an epoxy, vinylester or polyester thermosetting plastic. FRPs are commonly used in the aerospace, automobile, marine, and construction industries.
Fibreglass
Fibreglass (US: fiberglass) is a composite material. It is a fibre-reinforced polymer made of a plastic reinforced by fine fibres made of glass. The composite material may be called glass-reinforced plastic (GRP).
Fibreglass is cheaper and more flexible than carbon fibre. It is stronger than many metals (when compared by weight), and can be moulded into complex shapes. The plastic matrix is usually a thermoset polymer – such as epoxy or polyester resin, or it may be a thermoplastic.
The benefits of fibreglass include:
"Fiberglass" refers to the "complete glass fiber reinforced composite material", rather than just the glass fibre inside it.
Carbon fiber reinforced plastic
Carbon fiber reinforced plastic (CFRP or CRP), is a very strong, light and expensive composite material or fiber-reinforced plastic. Similar to glass-reinforced plastic, one uses commonly the name of its reinforcing fibers (carbon fiber) for the composite material. The plastic is most often epoxy, but other plastics, such as polyester, vinyl ester or nylon, are also sometimes used. Some composites contain both carbon fiber and other fibres such as kevlar, aluminium and fiberglass reinforcement. Less commonly, the terms graphite-reinforced plastic or graphite fiber reinforced plastic (GFRP) are also used.
It has many applications in aerospace and automotive fields, as well as in sailboats, and notably in modern bicycles and motorcycles, where these qualities are of importance. It is becoming increasingly common in small consumer goods as well, such as laptop computers, tripods, fishing rods, paintball equipment, racquet sports frames, stringed instrument bodies, classical guitar strings, and drum shells.
Carbon fiber
Carbon fiber (British English: carbon fibre) is a type of fiber that is made of carbon atoms. It is also sometimes called graphite fiber. It has the highest compressive strength of all the reinforcing materials (composites), and it has a high strength to weight ratio and low coefficient of thermal expansion. The density of carbon fiber is also much lower than the density of steel. Carbon fiber is in the form of several thousand long, thin strands of material that is composed of mostly carbon atoms.
Carbon fiber is most notably used to reinforce composite materials, particularly carbon fiber reinforced polymers. Reinforced carbon-carbon (RCC) is used structurally in high-temperature applications. The fiber is also used to filter high-temperature gases.
Molding a thin layer of carbon fibers significantly improves fire resistance of polymers or thermoset composites. This works because a dense, compact layer of carbon fibers efficiently reflects heat.
The increasing use of carbon fiber composites is displacing aluminum from aerospace applications in favor of other metals.
Coefficient
In mathematics, a coefficient is a constant multiplicative factor of a certain object. For example, the coefficient in "9x" is "9". A coefficient can also be a variable such as formula_1, formula_2 and formula_3.
The object can be such things as a variable, a vector, a function, etc. In some cases, the objects and the coefficients are indexed similarly, leading to expressions such as:
where "a" is the coefficient of the variable "x" for each "n" = 1, 2, 3, …
Coefficient (disambiguation)
Coefficient could have one of the following meanings:
Also,
Enrico Fermi
Enrico Fernando Fermi (September 29, 1901 — November 28, 1954) was an Italian-American physicist who worked on the first nuclear reactor and helped make quantum theory. He also was important to particle physics, and statistical mechanics. Fermi won the Nobel Prize in Physics in 1938 for his work on induced radioactivity. He built the world's first nuclear reactor. Fermi was one of the greatest scientists of the 20th century.
Fermi was born in Rome and went to a local grammar school. He was very good at maths and science and won a prize from Scuola Normale Superiore of Pisa. He went to the University of Pisa where he studied physics. In 1923 he was given a scholarship from the Italian government and went to Göttingen for more study. He was given a Rockefeller scholarship in 1924 and studied in Leyden. He came back to Italy at the end of 1924 and became Lecturer in Mathematical Physics and Mechanics at the University of Florence.
In 1926, Fermi discovered the statistical laws, now called Fermi statistics. These laws explain the actions of the particles which are subject to the Pauli exclusion principle, which are now called fermions. These are different to the particles called bosons which are explained by Bose-Einstein statistics. In 1927 he became Professor of Theoretical Physics at the University of Rome. He spent time studying electrodynamics, and began to closely look at the atomic nucleus. In 1934, using discoveries made by Wolfgang Pauli, Frédéric Joliot, Irène Joliot-Curie, he was able to show changes in almost every element bombarded with neutrons. This led to the discovery of slow neutrons, nuclear fission and making elements that were not in the Periodic Table.
Fermi expressed his concerns about the dangers of nuclear energy at one of the meetings of the University of Chicago before the end of the WWII.