Composite

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Etymology

Latin compositus, past participle of componere to put together. Introduced first in the architectural sense, the only one recognized by Johnson.

Definitions

  • 1 : made up of distinct parts: as a capitalized : relating to or being a modification of the Corinthian order combining angular Ionic volutes with the acanthus-circled bell of the Corinthian
b : of or relating to a very large family (Compositae syn. Asteraceae) of dicotyledonous herbs, shrubs, and trees often considered to be the most highly evolved plants and characterized by florets arranged in dense heads that resemble single flowers
c : factorable into two or more prime factors other than 1 and itself <8 is a positive composite integer>

Description

Composite materials (or composites for short) are engineered materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure.

History

Wood is a natural composite of cellulose fibers in a matrix of lignin. The most primitive manmade composite materials were straw and mud combined to form bricks for building construction; the Biblical Book of Exodus speaks of the Israelites being oppressed by Pharaoh, by being forced to make bricks without straw being provided. The ancient brick-making process can still be seen on Egyptian tomb paintings in the Metropolitan Museum of Art. The most advanced examples perform routinely on spacecraft in demanding environments. The most visible applications pave our roadways in the form of either steel and aggregate reinforced portland cement or asphalt concrete. Those composites closest to our personal hygiene form our shower stalls and bath tubs made of fiberglass. Solid surface, imitation granite and cultured marble sinks and counter tops are widely used to enhance our living experiences . Composites are made up of individual materials referred to as constituent materials. There are two categories of constituent materials: matrix and reinforcement. At least one portion of each type is required. The matrix material surrounds and supports the reinforcement materials by maintaining their relative positions. The reinforcements impart their special mechanical and physical properties to enhance the matrix properties. A synergism produces material properties unavailable from the individual constituent materials, while the wide variety of matrix and strengthening materials allows the designer of the product or structure to choose an optimum combination.[1]