Principles of Friction
In this lecture we will briefly discuss the frictional resistance that encountered in mechanics, where the friction may be defined as the contact resistance between two bodies when one of them moves or attend to move. From this definition it observed that this force always acting opposite to the motion.
Frictional force is divided in to three types:
a) Dry friction: this type of frictional force occurred when two contacted solid and unlubricated surfaces are sliding or attend to slide. This type of friction also called coulomb friction.
b) Fluid friction: when two different layers of fluid (in contact) moved in different velocities a frictional force will act among fluids particles which causing interaction between these layers. This force (in fluids) depends on the relative velocity and fluid viscosity.
c) Internal friction: this type of friction occurs when solid material subjected to cyclical loading, the permanent or temporary deformation that occurs may company with internal friction force. The mechanism of the internal frictional force is associated with the action of shear deformation.
In our lecture more details about the most common type of friction, dry friction.
Please, see the attached file
References
1- Dietmar Gross, et., al., 2009 "Engineering Mechanics 1-Static"Springer Heidelberg Dordrecht London New York.
2- Ferdinand L. Singer, 1975 " Engineering Mechanics- Static and Dynamic" Harper & Row, Publishers, Inc.
3- K L KUMAR, 2006 "Engineering Mechanics" Tata McGraw –Hill Publishing Company Limited.