ABSTRACT
Friction is a force that resists sliding. It is described in terms of a coefficient, and is usually erroneously assumed to be constant and specific to each material. The simple concepts obscure the causes of many problems in sliding systems, particularly in those that vibrate. Frictional vibration is an important problem in the measurement of friction and wear. Most theories of the friction of polymers are based on continuous contact of sliding surfaces. Another difficulty that the early adhesion theories of friction share with the classical laws of friction is that they apply to lightly loaded contact. During the time of the development of the ideas on adhesion, the interlocking theory also had its supporters. Friction is a dissipative process at contact interface with contribution from several mechanisms at different scale, ranging from phonon lattice vibrations at atom level to gross plastic deformation at micro level.
