×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Friction testing device

Friction testing device

Friction testing device

(OP)
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

RE: Friction testing device

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.

RE: Friction testing device

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.

RE: Friction testing device

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/

RE: Friction testing device

(OP)
Cory,

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

Best wishes

Marcus, Sweden

RE: Friction testing device

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?imgurl=http://www.minipocketscale.com/images/fish_scale/rw-hanging_lg.jpg&imgrefurl=http://www.minipocketscale.com/left_fish_scale/fish_scale.htm&h=300&w=217&sz=7&tbnid=NV75mkceZ_YJ:&;tbnh=111&tbnw=80&start=30&prev=/images%3Fq%3Dfish%2Bscale%26start%3D20%26hl%3Den%26lr%3D%26sa%3DN

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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources