WHAT ARE COMPOSITES?
Composites are combinations of non-metallic and sometimes metallic materials. They are most generally used as laminates and often as sandwich panels.
Laminae are typically fibre or particulate reinforced plastics - the most common being carbon, glass, Kevlar or Spectra/Dynema. The cores of structures can be Nomex, glass fibre or aluminium honeycombs, foam, balsa or Tufnol.
Composites are never homogeneous, isotropic or process independent, whereas metals generally are.
WHY USE COMPOSITES?
Composites are stiff, light weight and low density, meaning that they are more able to retain their shape under severe load cases. Their light weight improves stability and reduces severity of loading. The combination of stiffness and lightness increases response frequencies, reduces dynamic responses to shock, vibration and acceleration. They can even be cheaper than traditional manufacturing materials - in the right applications.