Friction testing device 1

[Marc77]

Hey all,

Do you guys ever come in contact with friction measurements for solid-solid body contacts and if so what type of equipment or methods do you use?

Best wishes

Marcus, Sweden

 

[CoryPad]

I have seen custom-built ramps that calculate the angle at which one solid slides against another. This allows calculation of friction coefficient through the tan [θ] relationship.

I also have seen devices that use two force cells - one vertical and one horizontal, and they are used to measure normal force and lateral force to move one solid with respect to the second solid.

Lastly, there are rotational devices (used mainly for threaded fastener joints) that measure input torque and reaction torque to calculate friction coefficient.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[JTreglio]

There are several companies that make pin-on-disc systems. They often advertise them as means to measure wear resistance, but the data they provide is primarily the coefficient of friction.

Jim Treglio
Molecular Metallurgy, Inc.

 

[Goahead]

One such device, used for rating lubricant properties and additives and for measuring wear resistance of materials under different conditions is called FALEX and is manufactured by Faville-LeVally. Also used for acceptance of case hardening processes.

http://www.welding-advisers.com/

 

[Marc77]

Cory,

Can you elaborate on the machine that uses two load cells or where one can find information about it...?

Best wishes

Marcus, Sweden

 

[CoryPad]

It was custom-built. One simple method to re-create this is determine accurately the mass of your moving solid. The force due to gravity then is N=ma. Connect another force measuring device, like a fish scale, see:

http://images.google.com/imgres?img...=/images?q=fish+scale&start=20&hl=en&lr=&sa=N

to your moving solid. Pull the fish scale and record the force F to initiate movement. The friction coefficient then is the ratio of F/N.

You can make the system much more accurate, etc. by using a universal testing machine (aka, tensile tester) to apply aand record a force, then use another force system to record the lateral force.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.