Composite material
Composite materials are made from two or more basic material. They are not just placed together. They are merged together. This create a material with useful properties unlike the individual elements.
The composite material as a whole may behave differently from either of its parts. For example, reinforced concrete (made of concrete and steel) has resistance to pressure and to bending forces. Bullet-proof glass (made of glass and plastic) is far more resistant to impact than either glass or plastic on their own.
Concrete itself is a composite material. It is one of the oldest man-made composites, used more than any other man-made material in the world.[1]
Wood is a natural composite of cellulose fibres in a matrix of lignin.[2][3] The earliest man-made composite materials were straw and mud combined to form bricks for building construction. This ancient brick-making process was documented by Egyptian tomb paintings. It is still used today in some places.
Fibre-reinforced polymers are in wide use today, as is glass-reinforced plastic.
The Biblical book of Exodus tells of the Israelites that were oppressed by Pharaoh and forced to make "bricks without straw".[4]
Composite Material Media
A black carbon fibre (used as a reinforcement component) compared to a human hair
Composites are formed by combining materials together to form an overall structure with properties that differ from that of the individual components
Concrete is a mixture of adhesive and aggregate, giving a robust, strong material that is very widely used.
Plywood is used widely in construction
Composite sandwich structure panel used for testing at NASA
Carbon fibre composite part.
Plot of the overall strength of a composite material as a function of fiber volume fraction limited by the upper bound (isostrain) and lower bound (isostress) conditions.
Figure a) shows the isostress condition where the composite materials are perpendicular to the applied force and b) is the isostrain condition that has the layers parallel to the force.
The graph depicts the three fracture modes a composite material may experience depending on the angle of misorientation relative to aligning fibres parallel to the applied stress.
Two different coordinate systems of material. The structure has a (1-2) coordinate system. The material has a (x-y) principal coordinate system.
Related pages
References
- ↑ Lomberg, Bjorn 2001. The skeptical environmentalist: measuring the real state of the world. Cambridge University Press, p138. ISBN 978-0-521-80447-9
- ↑ Hubbe M.A. & Lucia L.A. 207. The love-hate relationship present in lignocellulose materials. Bioresources. 2, 534.[1]
- ↑ Hon, David and Shiraishi, Nobuo (eds) 2001. Wood and cellulose chemistry. 2nd ed, New York: Marcel Dekker.
- ↑ The old brick-making process can still be seen on Egyptian tomb paintings in the Metropolitan Museum of Art.[2] Archived 2007-10-25 at the Wayback Machine.