Law of coulomb friction, Mechanical Engineering

Law of coulomb friction:

Coulomb in the year 1781 presented certain conclusions which are called as Coulomb's law of friction. These observations are based on experiments on block tending to move on the flat surface without rotation. These laws are appropriate at condition of impending slippage or once the slippage has begun. The laws are enunciated below:

1. The total force of friction, which can be developed, is not dependent on area of contact.

2. For low relative velocities between the sliding bodies, the total amount of frictional force is not dependent on velocity. But force required to start the motion is greater than that needed to maintain the motion.

3. The total frictional force, which can be developed is proportional to the normal reaction of surface of contact.

So, coefficient of friction (µ) can be defined as the ratio of the   limiting force of friction (F) to normal reaction (R) between the two bodies.

Therefore,

µ = Limiting force of friction/ Normal reaction = F/R

or, F = µ.R, In general µ < 1

The factor affecting coefficient of friction are:

1. The material of meeting bodies.

2. The roughness or smoothness of the meeting bodies.

3. The   temperature of environment.

Efforts to minimize it:

1. The use of proper lubrication can minimize friction.

2. Proper polishing of the surface minimizes it.

 

Posted Date: 10/17/2012 6:11:51 AM | Location : United States







Related Discussions:- Law of coulomb friction, Assignment Help, Ask Question on Law of coulomb friction, Get Answer, Expert's Help, Law of coulomb friction Discussions

Write discussion on Law of coulomb friction
Your posts are moderated
Related Questions
Q. Factors in the design of high temperature materials? There is typically little correlation between room temperature strength and high temperature strength of creep-resistant

Find out the final extension and the work done: Problem:  (i) A spring of stiffness 4 N/cm of extension is extended steadily yet the force of 20 N is reached. Find out th

Heat Dissipation : During clutch application, large amount of heat is generated. The rubbing surfaces should have sufficient area and mass to absorb the generated heat. The proper

Manufacturing Processes: Importance of Manufacturing: The importance of manufacturing is that a gives usable product from the ore of different metals and from different mate

Classificatio n of I.C. Engines: IC engines are classified as follows: 1 . Nature of thermodynamic cycles as:  Otto cycle engine, Diesel cycle engine and Dual combus

What is the velocity of the crosshead - crank: In the slider crank mechanism shown in Figure, the crank is rotating clockwise at 120 revolution/minute. What is the velocity of

V elocit y Ratio for Open Belt Drive: Figure Consider a simple belt drive (that is one driver and one follower) as shown in the figure given below Let D 1

Continuous Furnace: Parts to be treated are situated on several sort of conveyor that move into the furnaces as per to programmed heating cooling cycle. The time for unloadin

how an axial thrust is a generated in a helical gear

what is dry ness fraction?